Identify Light Elements In research published today in Nano Letters, physicists have delivered an unexpected boost for researchers with a new technique for 3D nanoscale elemental analysis for ion-electron microscope systems that allows the scientific community to take their work to the next level— particularly in the fields of energy storage and sustainability[21] An experiment at the Department of Energy's Fermilab has made a significant advance in the detection of neutrinos that hide themselves at lower energies. [20] Although three types of neutrino are known, scientists are searching for a possible fourth— the HYPERLINK "https://phys.org/tags/sterile+neutrino/" sterile neutrino, whose existence has been teased but never clearly confirmed. [19] A pair of researchers with the Niels Bohr Institute in Denmark has come up with a possible explanation for the excess of electron neutrinos detected by researchers at the IceCube Neutrino Observatory. [18] The largest liquid-argon neutrino detector in the world has just recorded its first particle tracks, signaling the start of a new chapter in the story of the international Deep Underground Neutrino Experiment (DUNE). [17] While these experiments seem miniature in comparison to others, they could reveal answers about neutrinos that have been hiding from physicists for decades. [16] In a paper published today in the European Physical Journal C, the ATLAS Collaboration reports the first high-precision measurement at the Large Hadron Collider (LHC) of the mass of the W boson. [15] A team of researchers at the University of Michigan has conducted a thought experiment regarding the nature of a universe that could support life without the weak force. [14] The international T2K Collaboration announces a first indication that the dominance of matter over antimatter may originate from the fact that neutrinos and antineutrinos behave differently during those oscillations. [13] Neutrinos are a challenge to study because their interactions with matter are so rare. Particularly elusive has been what's known as coherent elastic neutrino-nucleus scattering, which occurs when a neutrino bumps off the nucleus of an atom. [12] Lately, neutrinos – the tiny, nearly massless particles that many scientists study to better understand the fundamental workings of the universe – have been posing a problem for physicists. [11] Physicists have hypothesized the existence of fundamental particles called sterile neutrinos for decades and a couple of experiments have even caught possible hints of them. However, according to new results from two major international consortia, the chances that these indications were right and that these particles actually exist are now much slimmer. [10] The MIT team studied the distribution of neutrino flavors generated in Illinois, versus those detected in Minnesota, and found that these distributions can be explained most readily by quantum phenomena: As neutrinos sped between the reactor and detector, they were statistically most likely to be in a state of superposition, with no definite flavor or identity. [9] A new study reveals that neutrinos produced in the core of a supernova are highly localised compared to neutrinos from all other known sources. This result stems from a fresh estimate for an entity characterising these neutrinos, known as wave packets, which provide information on both their position and their momentum. [8] It could all have been so different. When matter first formed in the universe, our current theories suggest that it should have been accompanied by an equal amount of antimatter – a conclusion we know must be wrong, because we wouldn’t be here if it were true. Now the latest results from a pair of experiments designed to study the behaviour of neutrinos – particles that barely interact with the rest of the universe – could mean we’re starting to understand why. [7] In 2012, a tiny flash of light was detected deep beneath the Antarctic ice. A burst of neutrinos was responsible, and the flash of light was their calling card. It might not sound momentous, but the flash could give us tantalising insights into one of the most energetic objects in the distant universe. The light was triggered by the universe's most elusive particles when they made contact with a remarkable detector, appropriately called IceCube, which was built for the very purpose of capturing rare events such as this. [6] Neutrinos and their weird subatomic ways could help us understand highenergy particles, exploding stars and the origins of matter itself. [5] PHYSICS may be shifting to the right. Tantalizing signals at CERN’s Large Hadron Collider near Geneva, Switzerland, hint at a new particle that could end 50 years of thinking that nature discriminates between left and righthanded particles. [4] The Weak Interaction transforms an electric charge in the diffraction pattern from one side to the other side, causing an electric dipole momentum change, which violates the CP and Time reversal symmetry. The Neutrino Oscillation of the Weak Interaction shows that it is a General electric dipole change and it is possible to any other temperature dependent entropy and information changing diffraction pattern of atoms, molecules and even complicated biological living structures. New characterization methods developed to identify light elements .................................................. 5 Identifying lower-energy neutrinos with a liquid-argon particle detector ............................................ 6 Fermilab scientists lead quest to find elusive fourth kind of neutrino ................................................. 8 Making a (dis)appearance ............................................................................................................... 8 Components from three continents ................................................................................................. 9 Possible explanation for excess of electron neutrinos detected by IceCube Neutrino Observatory....................................................................................................................................... 10 First particle tracks seen in prototype for international neutrino experiment .................................... 11 Neutrino experiments look to reveal big answers about how these fundamental particles interact with matter ............................................................................................................................ 13 The Mysteries of the Neutrino ....................................................................................................... 14 Searching for a Coherent Answer with COHERENT .................................................................... 14 Finding Precision with PROSPECT .............................................................................................. 16 First high-precision measurement of the mass of the W boson at the LHC ..................................... 17 Imagining the possibility of life in a universe without the weak force ............................................... 18 Possible explanation for the dominance of matter over antimatter in the Universe ......................... 18 World's smallest neutrino detector observes elusive interactions of particles ................................. 20 No gigantic lab ............................................................................................................................... 20 Neutrino alley ................................................................................................................................. 21 In search of 'sterile' neutrinos ........................................................................................................... 22 PROSPECTing for Neutrinos ........................................................................................................ 22 Next Steps ..................................................................................................................................... 23 As hunt for sterile neutrino continues, mystery deepens .................................................................. 23 Weird quantum effects stretch across hundreds of miles ................................................................. 24 A subatomic journey across state lines ......................................................................................... 25 A flipped inequality ........................................................................................................................ 26 Surprising neutrino decoherence inside supernovae ....................................................................... 27 Neutrinos hint at why antimatter didn’t blow up the universe ........................................................... 27 Puff of radiation ............................................................................................................................. 28 Flavour changers ........................................................................................................................... 28 What the universe's most elusive particles can tell us about the universe's most energetic objects ............................................................................................................................................... 29 The antisocial particle that came in from the cold ......................................................................... 29 Nucleus of a galaxy ....................................................................................................................... 30 An exciting problem ....................................................................................................................... 31 Neutrinos: Ghosts of the Universe .................................................................................................... 31 The Ice Telescope Cometh ........................................................................................................... 33 Neutrino Mysteries......................................................................................................................... 33 Heavyweight Competition .............................................................................................................. 34 When Lefties Turn Right ................................................................................................................ 35 Cracked Mirror? ............................................................................................................................. 35 Seeing Stars .................................................................................................................................. 35 Double Trouble .............................................................................................................................. 38 Flying High ..................................................................................................................................... 39 Neutrino Gold................................................................................................................................. 41 Possible new particle hints that universe may not be left-handed.................................................... 41 Asymmetry in the interference occurrences of oscillators ................................................................ 43 Spontaneously broken symmetry in the Planck distribution law....................................................... 44 The structure of the proton ................................................................................................................ 46 The Weak Interaction ........................................................................................................................ 46 The General Weak Interaction .......................................................................................................... 47 Fermions and Bosons ....................................................................................................................... 48 The fermions' spin ............................................................................................................................. 48 The source of the Maxwell equations ............................................................................................... 49 The Special Relativity........................................................................................................................ 50 The Heisenberg Uncertainty Principle .............................................................................................. 50 The Gravitational force ...................................................................................................................... 50 The Graviton...................................................................................................................................... 51 What is the Spin? .............................................................................................................................. 51 The Casimir effect ............................................................................................................................. 52 The Fine structure constant .............................................................................................................. 52 Conclusions ....................................................................................................................................... 53 References ........................................................................................................................................ 53 Author: George Rajna New characterization methods developed to identify light elements In research published today in Nano Letters, physicists have delivered an unexpected boost for researchers with a new technique for 3D nanoscale elemental analysis for ion-electron microscope systems that allows the scientific community to take their work to the next level—particularly in the fields of energy storage and sustainability Scientists from leading scientific instrumentation company Thermo Fisher Scientific worked with the ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS) to create a device that can be retrofitted to existing focused ion beam systems (FIBS). This device reimagines how the FIB is used—moving it beyond a tool for sputtering to an engine for elemental characterization, collecting and analyzing the photons emitted during the sputtering process. This new method offers a number of improvements to other characterization methods. In particular, it offers a resolution of 15 nanometers, a significant improvement on the 1-micron resolution of electronbased EDX technique. Additionally, it can detect hard-to-characterize elements such as hydrogen and lithium. Lead author and Senior Scientist at Thermo Fisher Scientific Garrett Budnik says, "the characterization of light elements has always been a challenge. This new device fills what was previously a gap in technology, paving the way for further scientific advancement. "When that happens and researchers can investigate their problems with new techniques, new discoveries are made." University of Technology Sydney (UTS) post-doctoral researcher and co-author John Scott says, "This research was geared toward enabling other researchers to solve problems in an efficient way. Integrating elemental analysis as part of the sputtering process optimizes the characterization workflow, creating a better experience for all involved. We've developed this new technique so others can develop new technologies in a range of fields." Budnik is the third Thermo Fisher Scientific employee to engage with the university in an industry-relevant Ph.D., working on projects designed by Thermo Fisher Scientific based on their deep understanding of gaps in the commercial market and industry-leading technology development. TMOS Chief Investigator Milos Toth, who worked at Thermo Fisher Scientific as a research scientist before joining UTS as a professor, says, "Shared research between industry and academia are successful because they result in commercially-driven research. On their own, academic researchers might invest their energy in research that has little market appeal. Industry might develop rigorously-tested technology without fully understanding the fundamental science behind it. Together, they can make a significant contribution to society." Scott says, "This research was only possible because we had access to Thermo Fisher's engineers. Our FIB is probably the most heavily modified microscope anyway and that's because we could tap into the people who designed it, people who could help us tear it apart and put it back together." Discussing the future of their research, Budnik says "We've pushed this detection system to its classical limit. It has been optimized to the point where the only place to go next is using metasurfaces. That's the natural next step." [21] Identifying lower-energy neutrinos with a liquid-argon particle detector An experiment at the Department of Energy's Fermilab has made a significant advance in the detection of neutrinos that hide themselves at lower energies. The ArgoNeuT experiment recently demonstrated for the first time that a particular class of particle detector—those that use liquid argon—can identify signals in an energy range that particle physicists call the "MeV range." It's the first substantive step in confirming that researchers will be able to detect a wide energy range of neutrinos—even those at the harder-to-catch, lower energies—with the international Deep Underground Neutrino Experiment, or DUNE, hosted by Fermilab. DUNE is scheduled to start up in the mid2020s. Neutrinos are lightweight, elusive and subtle particles that travel close to the speed of light and hold clues about the universe's evolution. They are produced in radioactive decays and other nuclear reactions, and the lower their energy, the harder they are to detect. In general, when a neutrino strikes an argon nucleus, the interaction generates other particles that then leave detectable trails in the argon sea. These particles vary in energy. Scientists are fairly adept at teasing out higher-energy particles—those with more than 100 MeV (or megaelectronvolts)—from their liquid-argon detector data. These particles zip through the argon, leaving behind what look like long trails in visual displays of the data. Sifting out particles in the lower, single-digit-MeV range is tougher, like trying to extract the better hidden needles in the proverbial haystack. That's because lower-energy particles don't leave as much of a trace in the liquid argon. They don't so much zip as blip. Indeed, after simulating neutrino interactions with liquid argon, ArgoNeuT scientists predicted that MeVenergy particles would be produced and would be visible as tiny blips in the visual data. Where higherenergy particles show as streaks in the argon, the MeV particles' telltale signature would be small dots. This 4-minute animation shows how the international Deep Underground Neutrino Experiment will help scientists understand how the universe works. DUNE will use a huge particle detector a mile underground to embark on a mission with three major …more And this was the challenge ArgoNeuT researchers faced: How do you locate the tiny blips and dots in the data? And how do you check that they signify actual particle-interactions and are not merely noise? The typical techniques, the methods for identifying long tracks in liquid argon, wouldn't apply here. Researchers would have to come up with something different. And so they did: ArgoNeuT developed a method to identify and reveal blip-like signals from MeV particles. They started by comparing two different categories: blips accompanied by known neutrino events and blips unaccompanied by neutrino events. Finally, they developed a new low-energy-specific reconstruction technique to analyze ArgoNeuT's actual experimental data to look for them. And they found them. They observed the blip signals, which matched the simulated results. Not only that, but the signals came through loud and clear: ArgoNeuT identified MeV signals as a 15 sigma excess, far higher than the standard for claiming an observation in particle physics, which is 5 sigma (which means that there's a 1 in 3.5 million chance that the signal is a fluke.) ArgoNeuT's result demonstrates a capacity of crucial importance for measuring MeV neutrino events in liquid argon. Intriguingly, neutrinos born inside a supernova also fall into MeV range. ArgoNeuT's result gives DUNE scientists a leg up in one of its research goals: to improve our understanding of supernovae by studying the torrent of neutrinos that escape from inside the exploding star as it collapses. The enormous DUNE particle detector, to be located underground at Sanford Lab in South Dakota, will be filled with 70,000 tons of liquid argon. When neutrinos from a supernova traverse the massive volume of argon below Earth's surface, some will bump into the argon atoms, producing signals collected by the DUNE detector. Scientists will use the data amassed by DUNE to measure supernova neutrino properties and fill in the picture of the star that produced them, and even potentially witness the birth of a black hole. Particle detectors picked up a handful of neutrino signals from a supernova in 1987, but none of them were liquid-argon detectors. (Other neutrino experiments use, for example, water, oil, carbon, or plastic as their detection material of choice.) DUNE scientists needed to understand what the lower-energy signals from a supernova would look like in argon. The ArgoNeuT collaboration is the first experiment to help answer that question, providing a kind of first chapter in the guidebook on what to look for when a supernova neutrino meets argon. Its achievement could bring us a little closer to learning what these messengers from outer space will have to tell us. [20] Fermilab scientists lead quest to find elusive fourth kind of neutrino Neutrinos, ghostly fundamental particles that are famously difficult to study, could provide scientists with clues about the evolution of the universe. They are so difficult to catch, in fact, that it's possible there's a fourth type that's been hiding right under our noses for decades. Scientists at the UChicago-affiliated Fermi National Accelerator Laboratory, site of the most extensive neutrino research in the world, are leading an international collaboration to explore the possibility of a completely new particle. Although three types of neutrino are known, scientists are searching for a possible fourth—the sterile neutrino, whose existence has been teased but never clearly confirmed. Major components for the new neutrino experiment are arriving from around the world to be integrated into the upcoming Short-Baseline Near Detector, or SBND, at Fermilab. "The short-baseline program aims to address interesting results from previous experiments that could be hinting at a new class of neutrinos, which would open up a completely new, unexpected area in neutrino physics," said David Schmitz, SBND co-spokesperson and assistant professor of physics at the University of Chicago. "But no matter what we find, the results should give us clarity on this long-standing puzzle." At Fermilab, located about 45 miles west of Chicago, three detectors perch along a beam of neutrinos generated by Fermilab's particle accelerators. Of the three, the new detector will sit closest to the beam source, just 360 feet away. (The other two, MicroBooNE and ICARUS, are 1,500 feet and 2,000 feet from the source, respectively.) "The reason you have three detectors is that you want to sample the neutrino beam along the beamline at different distances," said Fermilab neutrino scientist Ornella Palamara, the other spokesperson for the project. As neutrinos pass through one detector after the other, some of them leave behind traces in the detectors. Scientists will analyze this information to search for firm evidence of the hypothesized but never seen member of the neutrino family. Making a (dis)appearance Neutrinos come in one of three "flavors": electron, muon and tau. They change from one flavor into another as they travel through space, which is called oscillation. Neutrinos are known to oscillate in and out of the three flavors, but only further evidence will help scientists determine whether they also oscillate into a fourth type—a sterile neutrino. If these sterile neutrinos exist, they don't interact with matter at all. (The neutrinos we're familiar with do interact, but only rarely.) Results from other experiments have hinted at the possibility of the sterile neutrino's existence, but so far, no one has confirmed it. Three detectors perch along a beam of neutrinos generated by Fermilab’s particle accelerators, each checking the stream for evidence of a possible fourth type of neutrino. Credit: Fermilab SBND, as the first detector in the beam, will record the number of electron and muon neutrinos that pass through it before oscillation can occur. The vast majority of them—about 99.5 percent—will be muon neutrinos. By the time of their arrival at the far detectors, MicroBooNE and ICARUS, a few out of every thousand muon neutrinos may have converted into electron neutrinos. Two possible outcomes could indicate the existence of the new particle. One is that the far detectors see more electron neutrinos than expected. This could be evidence that sterile neutrinos are also present: The neutrinos could be converting into and out of sterile neutrino states in a way that produces an excess of electron neutrinos. The other is that the far detectors see fewer muon neutrinos than expected—the muon neutrinos spotted in SBND "disappear"—because they converted into sterile neutrinos. "Having a single experiment where we can see electron neutrino appearance and muon neutrino disappearance simultaneously and make sure their magnitudes are compatible with one another is enormously powerful for trying to discover sterile neutrino oscillations," said Schmitz. "The near detector substantially improves our ability to do so." Components from three continents The first of four anode plane assemblies, highly sensitive electronic components, came to Fermilab in October. More are on their way. The anode plane assemblies, four in all, are part of a 4-by-4-by-5-meter detector that will be suspended inside a cryogenic tank filled with liquid argon at -300 degrees Fahrenheit. Each assembly is a huge frame covered with thousands of delicate sense wires, designed to track particles that come off neutrinos colliding with argon atoms in the tank. SBND will also be a testing ground for some of the technologies, including the anode plane assemblies, that will be used in the international Deep Underground Neutrino Experiment, known as DUNE, a megascience experiment hosted by Fermilab that is currently under construction in South Dakota. Institutions in Europe, South America and the United States are helping build SBND's various components. In all, more than 20 institutions on three continents are involved in the effort. Another dozen are collaborating on software tools to analyze data once the detector is operational, Schmitz said. "Being part of an international collaboration is great," Palamara said. "Of course, there are challenges, but it's fantastic to see people coming from all around the world to work on the program. Having pieces of the detector built in different places and then seeing everything come together is exciting." Assembly of SBND is expected to finish in fall 2019, after which the detector will be installed in its building along the accelerator-generated neutrino beam. SBND is scheduled to begin receiving neutrinos by the end of 2020. [19] Possible explanation for excess of electron neutrinos detected by IceCube Neutrino Observatory A pair of researchers with the Niels Bohr Institute in Denmark has come up with a possible explanation for the excess of electron neutrinos detected by researchers at the IceCube Neutrino Observatory. In their paper published in the journal Physical Review Letters, Peter Denton and Irene Tamborra describe their ideas and how they arrived at them. The IceCube Neutrino Observatory is located on and below the ice in Antarctica—unlike other observatories, it is pointed downwards. This allows for detecting cosmic particles after they have passed all the way through the Earth. This approach means that the Earth can be used to filter out unwanted noise. It also provides a way to track the behavior of the particles after they pass through the planet or after they have collided with other particles. In this new effort, the researchers have offered a possible explanation for an anomaly detected at the observatory. Neutrinos at the observatory are studied in two different ways. In the first, researchers study the tracks they make as they move through a detector. In the second, they study particles that cause light to be emitted when they smash into ice particles. Scientists studying the neutrinos have found an apparent anomaly, one that is in need of an explanation. The anomaly involves the ratio of neutrino types that are detected at the observatory. Prior research has found that there are three kinds of neutrinos—electron, muon and tau—and that they should be found in equal numbers. But the detector consistently detects many more electron neutrinos than the other two types. Denton and Tamborra suggest this discrepancy can be explained by tau and muon neutrinos decaying into a different particle called a majoron. And this is where it gets truly interesting because majorons are a proposed dark matter particle. Majorons have been proposed as a dark matter particle that could allow a neutrino to have mass. If so, that would help explain experiments that have shown that neutrinos actually do have mass. If it can be shown that muon and tau neutrinos decay to them, that would not only explain the anomaly, but it would also offer more credence to theories surrounding dark matter. [18] First particle tracks seen in prototype for international neutrino experiment The largest liquid-argon neutrino detector in the world has just recorded its first particle tracks, signaling the start of a new chapter in the story of the international Deep Underground Neutrino Experiment (DUNE). DUNE's scientific mission is dedicated to unlocking the mysteries of neutrinos, the most abundant (and most mysterious) matter particles in the universe. Neutrinos are all around us, but we know very little about them. Scientists on the DUNE collaboration think that neutrinos may help answer one of the most pressing questions in physics: why we live in a universe dominated by matter. In other words, why we are here at all. The enormous ProtoDUNE detector—the size of a three-story house and the shape of a gigantic cube—was built at CERN, the European laboratory for particle physics, as the first of two prototypes for what will be a much, much larger detector for the DUNE project, hosted by the U.S. Department of Energy's Fermi National Accelerator Laboratory in the United States. When the first DUNE detector modules record data in 2026, they will each be 20 times larger than these prototypes. There will be four modules in total. It is the first time CERN is investing in infrastructure and detector development for a particle physics project in the United States. Inside the first ProtoDUNE detector, before it was filled with liquid argon. Credit: CERN The first ProtoDUNE detector took two years to build and eight weeks to fill with 800 tons of liquid argon, which needs to be kept at temperatures below minus 184 degrees Celsius (minus 300 degrees Fahrenheit). The detector records traces of particles in that argon both from cosmic rays and a beam created at CERN's accelerator complex. Now that the first tracks have been seen, scientists will operate the detector over the next several months to test the technology in depth. "Only two years ago we completed the new building at CERN to house two large-scale prototype detectors that form the building blocks for DUNE," said Marzio Nessi, head of the Neutrino Platform at CERN. "Now we have the first detector taking beautiful data, and the second detector, which uses a different approach to liquid-argon technology, will be online in a few months." The technology of the first ProtoDUNE detector will be the same to be used for the first of the DUNE detector modules in the United States, which will be built a mile underground at the Sanford Underground Research Facility in South Dakota. More than 1,000 scientists and engineers from 32 countries spanning five continents—Africa, Asia, Europe, North America and South America—are working on the development, design and construction of the DUNE detectors. The groundbreaking ceremony for the caverns that will house the experiment was held in July 2017. "Seeing the first particle tracks is a major success for the entire DUNE collaboration," said DUNE cospokesperson Stefan Soldner-Rembold of the University of Manchester, UK. "DUNE is the largest collaboration of scientists working on neutrino research in the world, with the intention of creating a cutting-edge experiment that could change the way we see the universe." When neutrinos enter the detectors and smash into the argon nuclei, they produce charged particles. Those particles leave ionization traces in the liquid, which can be seen by sophisticated tracking systems able to create three-dimensional pictures of otherwise invisible subatomic processes. "CERN is proud of the success of the Neutrino Platform and enthusiastic about being a partner in DUNE, together with institutions and universities from its member states and beyond," said Fabiola Gianotti, director-general of CERN. "These first results from ProtoDUNE are a nice example of what can be achieved when laboratories across the world collaborate. Research with DUNE is complementary to research carried out by the LHC and other experiments at CERN; together they hold great potential to answer some of the outstanding questions in particle physics today." DUNE will not only study neutrinos, but their antimatter counterparts as well. Scientists will look for differences in behavior between neutrinos and antineutrinos, which could give us clues as to why the visible universe is dominated by matter. DUNE will also watch for neutrinos produced when a star explodes, which could reveal the formation of neutron stars and black holes, and will investigate whether protons live forever or eventually decay. Observing proton decay would bring us closer to fulfilling Einstein's dream of a grand unified theory. [17] Neutrino experiments look to reveal big answers about how these fundamental particles interact with matter Except in horror movies, most scientific experiments don't start with scientists snooping around narrow, deserted hallways. But a tucked-away location in the recesses of the Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) provided exactly what Yuri Efremenko was looking for. Efremenko, an ORNL researcher and University of Tennessee at Knoxville professor, is the spokesperson for the COHERENT experiment, which is studying neutrinos. The team uses five particle detectors to identify a specific interaction between neutrinos and atomic nuclei. The most abundant particles in the universe, neutrinos are extremely light and have no electric charge. They interact very little with other particles. In fact, trillions pass through the Earth every second, leaving no impression. Needless to say, they're notoriously difficult to detect. At first, the team surveyed a bustling area near the Spallation Neutron Source (SNS), a DOE Office of Science user facility at ORNL in Tennessee. The neutrons the SNS produces drive 18 different instruments that surround the SNS like spokes on a wheel. The SNS also produces neutrinos, which fly off in all directions from the particle accelerator's target. But putting the neutrino detectors on the same floor as the SNS would expose the devices to background particles that would increase uncertainties. "We were really fortunate to go into the basement one day," said David Dean, ORNL's Physics Division Director. After moving some water barrels to the side and conducting background tests, they were in business. The basement location would protect the machines from exposure to background particles. Once scientists installed the experiment's detectors, they nicknamed the hallway "Neutrino Alley." The experiment, called COHERENT, poses a stark contrast to most other neutrino experiments. To catch a glimpse of these miniscule particles, most experiments use incredibly large machines, often in remote locations. One is located at the South Pole, while another shoots neutrino beams hundreds of miles to a far detector. Besides its mundane location, COHERENT's main detector is barely bigger than a milk jug. In fact, it's the smallest working neutrino detector in the world. But COHERENT and a sister experiment at ORNL, PROSPECT, are showing that neutrino experiments don't have to be enormous to make big discoveries. These two modest experiments supported by DOE's Office of Science are poised to fill some major gaps in our understanding of this strange particle. The Mysteries of the Neutrino While neutrinos are some of the smallest particles in the universe, investigating them may reveal massive insights. "Neutrinos tell us a tremendous amount about how the universe is created and held together," said Nathaniel Bowden, a scientist at DOE's Lawrence Livermore National Laboratory and co-spokesperson for PROSPECT. "There's no other way to answer a lot of the questions that we find ourselves having." Understanding how neutrinos interact may even help us understand why matter—and everything made out of it—exists at all. But neutrinos haven't made answering these questions easy. There are three different types of neutrinos, each of which behaves differently. In addition, they change type as they travel. Some scientists have proposed a not-yet-seen particle called the sterile neutrino. Physicists theorize that if sterile neutrinos exist, they would interact with other particles even less than regular ones do. That would make them nearly impossible to detect. But that's a big "if." A sterile neutrino would be the first particle not predicted by the Standard Model, physicists' summary of how the universe functions. "Neutrinos may hold the clue to discovering particle physics beyond the Standard Model," said Karsten Heeger, a Yale University professor and co-spokesperson for PROSPECT. Searching for a Coherent Answer with COHERENT A team of scientists from ORNL, other DOE national laboratories, and universities designed the COHERENT experiment to identify a specific interaction between neutrinos and nuclei. While physicists had predicted this interaction more than 40 years ago, they had never detected it. Most neutrinos only interact with individual protons and neutrons. But if a neutrino's energy is low enough, it should interact with an entire nucleus rather than its individual parts. Theorists proposed that when a low-energy neutrino approaches a nucleus, the two particles exchange an elementary particle called a Z boson. As the neutrino releases the Z boson, the neutrino bounces away. As the nucleus receives the Z boson, the nucleus recoils slightly. That interaction is called coherent elastic neutrino-nucleus scattering. Because most nuclei are much bigger than individual protons or neutrons, scientists should see this type of interaction more frequently than interactions driven by higher energy neutrinos. By "seeing" the tiny recoil energy, COHERENT's gallon-sized detectors make it possible for scientists to study neutrino properties. Bjorn Scholz (left) from the University of Chicago and Grayson Rich of the University of North Carolina at Chapel Hill and the Triangle Universities Nuclear Laboratory show off the world's smallest neutrino detector, which is part of the …more "It's kind of cool that you could actually see an interaction of neutrinos with something you can hold in your hand," said Kate Scholberg, a Duke University professor and collaborator on COHERENT. But none of this would be possible without ORNL's SNS. The neutrinos the SNS produces pass through concrete and gravel to reach ORNL's basement. They have just the right energy to induce this particular interaction. The SNS's pulsed beam also allows scientists to filter out background "noise" from other particles. "There's quite a flux of neutrinos that was being wasted, at the SNS, so to speak. It is the perfect source for coherent scattering—the cat's pajamas," said Juan Collar, a University of Chicago professor and collaborator on COHERENT. After running for 15 months, COHERENT caught neutrinos in the act of handing off Z bosons 134 times. Looking over his graduate student's shoulder as he crunched the data, Collar was thrilled to see that the results came out exactly as expected. "When we finally looked at the processed, full dataset, we went 'wheeeeeee!'" he said. Measuring this phenomenon – neutrino-nucleus elastic scattering – gives physicists a new and versatile tool to understand neutrinos. "It's opened our window to look for the physics beyond the Standard Model," said Efremenko. Using this interaction, scientists may be better able to understand how supernovae explode and produce neutrinos. While these detectors are mainly used for fundamental research, their tiny size could also be useful for other applications. Nuclear reactors produce different types and amounts of neutrinos, depending on whether they produce energy or weapons-grade material. A detector as small as COHERENT's could make the effort to monitor nuclear facilities much easier. Finding Precision with PROSPECT While COHERENT looked for a specific phenomenon, the PROSPECT experiment will focus on making incredibly precise measurements of neutrinos from a nuclear reactor as they change type. Past nuclear reactor experiments have resulted in measurements that depart from theory. The PROSPECT team has designed an experiment that can explore any discrepancies, eliminate possible sources of error, or even discover the sterile neutrino. Compared to previous neutrino reactor experiments, PROSPECT will be able to more accurately measure the number and type of neutrinos, the distance they travel from the reactor, and their energy. PROSPECT differs from other experiments in that its detector has multiple sections instead of one single chamber. This allows scientists to measure and compare various neutrino oscillation lengths – that is, how far from the reactor neutrinos are changing type. If sterile neutrinos exist, this detector design may also enable scientists to observe regular neutrinos transitioning into sterile neutrinos. In theory, this new form of neutrinos should appear at a specific distance from the detector core. The High Flux Isotope Reactor (HFIR), a DOE Office of Science user facility at ORNL, will provide PROSPECT with its neutrinos. Commercial nuclear reactors use a variety of uranium and plutonium fuels with different combinations of isotopes. This results in a broad spectrum of neutrino energies. That makes it difficult to pinpoint which isotopes are producing which neutrinos. As a research reactor, HFIR only uses one isotope of uranium: uranium-235. By measuring the antineutrinos from that single isotope, the PROSPECT team can better understand how all nuclear reactors produce neutrinos. Scientists in the PROSPECT collaboration recently finished building a detector at Yale University's Wright Laboratory. While the active detector region is much bigger than COHERENT's milk-jug sized detector, it's still only four feet wide and weighs about five tons. Compared to detectors that weigh thousands of tons, this experiment too runs on the small side. Once PROSPECT is completed and in place, it will take data for three years. While these experiments seem miniature in comparison to others, they could reveal answers about neutrinos that have been hiding from physicists for decades. It may just be a matter of scientists knowing where and how to look, even if that's down a seemingly ordinary storage hallway. [16] First high-precision measurement of the mass of the W boson at the LHC In a paper published today in the European Physical Journal C, the ATLAS Collaboration reports the first high-precision measurement at the Large Hadron Collider (LHC) of the mass of the W boson. This is one of two elementary particles that mediate the weak interaction – one of the forces that govern the behaviour of matter in our universe. The reported result gives a value of 80370±19 MeV for the W mass, which is consistent with the expectation from the Standard Model of Particle Physics, the theory that describes known particles and their interactions. The measurement is based on around 14 million W bosons recorded in a single year (2011), when the LHC was running at the energy of 7 TeV. It matches previous measurements obtained at LEP, the ancestor of the LHC at CERN, and at the Tevatron, a former accelerator at Fermilab in the United States, whose data made it possible to continuously refine this measurement over the last 20 years. The W boson is one of the heaviest known particles in the universe. Its discovery in 1983 crowned the success of CERN's Super proton-antiproton Synchrotron, leading to the Nobel Prize in physics in 1984. Although the properties of the W boson have been studied for more than 30 years, measuring its mass to high precision remains a major challenge. "Achieving such a precise measurement despite the demanding conditions present in a hadron collider such as the LHC is a great challenge," said the physics coordinator of the ATLAS Collaboration, Tancredi Carli. "Reaching similar precision, as previously obtained at other colliders, with only one year of Run 1 data is remarkable. It is an extremely promising indication of our ability to improve our knowledge of the Standard Model and look for signs of new physics through highly accurate measurements." The Standard Model is very powerful in predicting the behaviour and certain characteristics of the elementary particles and makes it possible to deduce certain parameters from other well-known quantities. The masses of the W boson, the top quark and the Higgs boson for example, are linked by quantum physics relations. It is therefore very important to improve the precision of the W boson mass measurements to better understand the Higgs boson, refine the Standard Model and test its overall consistency. Remarkably, the mass of the W boson can be predicted today with a precision exceeding that of direct measurements. This is why it is a key ingredient in the search for new physics, as any deviation of the measured mass from the prediction could reveal new phenomena conflicting with the Standard Model. The measurement relies on a thorough calibration of the detector and of the theoretical modelling of the W boson production. These were achieved through the study of Z boson events and several other ancillary measurements. The complexity of the analysis meant it took almost five years for the ATLAS team to achieve this new result. Further analysis with the huge sample of now-available LHC data, will allow even greater accuracy in the near future. [15] Imagining the possibility of life in a universe without the weak force A team of researchers at the University of Michigan has conducted a thought experiment regarding the nature of a universe that could support life without the weak force. In their paper uploaded to the ArXiv preprint server, the researchers suggest life could be possible in such an alternative universe, but it would definitely be different from what we observe in ours. Physicists have debated the possibility of the existence of alternate universes for some time, though there is no evidence they exist. In this new thought experiment, the team at UM wondered if one or more of the laws of physics that we have discovered in this universe might not exist in others—if they do exist. Because it would be hard to imagine a universe that could exist without gravity and the strong and electromagnetic forces, the team instead focused on the weak force—the one behind such things as neutrons decaying into protons. The team wondered what a universe without the weak force would look like. To visualize it, they created a simulation of such a universe starting from the Big Bang. In the simulation, matter was still created and condensed into stars, but from there on, things would be different, because in our universe, the weak force is responsible for the creation of the heavier elements. In a universe without the weak force, the existence of anything other than stars would require more free protons and fewer neutrons (because they could not decay). In such a universe, neutrons and protons could link up to make deuterium. Stars fueled by deuterium instead of hydrogen, the researchers note, would still shine, they would just look different—likely redder and larger. But such stars could also serve as the source of all of the elements in the periodic table prior to iron, and the stellar winds could carry them out into space. If planets happened to form, they further note, they could hold water made from deuterium rather than hydrogen—and it is not impossible to imagine, they suggest, life forms made with deuterium water. [14] Possible explanation for the dominance of matter over antimatter in the Universe An electron-neutrino interaction observed by the T2K experiment. The neutrino interacts with a water molecule in the detector volume producing an electron which in turn emits Cherenkov light while travelling across the detector. This light is collected by special photo-sensors and converted into a measurable electric signal. Credit: © Albert Einstein Center for Fundamental Physics (AEC), Laboratory for High Energy Physics Neutrinos and antineutrinos, sometimes called ghost particles because difficult to detect, can transform from one type to another. The international T2K Collaboration announces a first indication that the dominance of matter over antimatter may originate from the fact that neutrinos and antineutrinos behave differently during those oscillations. This is an important milestone towards the understanding of our Universe. A team of particle physicists from the University of Bern provided important contributions to the experiment. The Universe is primarily made of matter and the apparent lack of antimatter is one of the most intriguing questions of today's science. The T2K collaboration, with participation of the group of the University of Bern, announced today in a colloquium held at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, that it found indication that the symmetry between matter and antimatter (so called "CP-Symmetry") is violated for neutrinos with 95% probability. Different Transformation of Neutrinos and Antineutrinos Neutrinos are elementary particles which travel through matter almost without interaction. They appear in three different types: electron- muon- and tau-neutrinos and their respective antiparticle (antineutrinos). In 2013 T2K discovered a new type of transformation among neutrinos, showing that muon-neutrinos transform (oscillate) into electron-neutrinos while travelling in space and time. The outcome of the latest T2K study rejects with 95% probability the hypothesis that the analogous transformation from muon-antineutrinos to electron-antineutrinos takes place with identical chance. This is a first indication that the symmetry between matter and antimatter is violated in neutrino oscillations and therefore neutrinos also play a role in the creation of the matterantimatter asymmetry in the universe. "This result is among the most important findings in neutrino physics over the last years," said Prof. Antonio Ereditato, director of the Laboratory of High Energy Physics of the University of Bern and leader of the Bern T2K group, "and it is opening the way to even more exciting achievements, pointing to the existence of a tiny but measurable effect." Ereditato added: "Nature seems to indicate that neutrinos can be responsible for the observed supremacy of matter over antimatter in the Universe. What we measured justifies our current efforts in preparing the next scientific enterprise, DUNE, the ultimate neutrino detector in USA, which should allow reaching a definitive discovery." In the T2K experiment a muon-neutrino beam is produced at the Proton Accelerator Research Complex (J-PARC) in Tokai on the east coast of Japan and is detected 295 kilometres away by the gigantic Super-Kamiokande underground detector ("T2K" stands for "Tokai to Kamiokande"). The neutrino beam needs to be fully characterized immediately after production, that means before neutrinos start to oscillate. For this purpose, the ND280 detector was built and installed close to the neutrino departing point. Researchers from the University of Bern, together with colleagues from Geneva and ETH Zurich, and other international institutions, contributed to the design, realization and operation of ND280. The group of Bern, in particular, took care of the large magnet surrounding the detector and built and operated the so-called muon monitor, a device needed to measure the intensity and the energy spectrum of the muon particles produced together with neutrinos. The Bern group is currently very active in determining the probability of interaction of neutrinos with the ND280 apparatus: an important ingredient to reach high-precision measurements such as the one reported here. [13] World's smallest neutrino detector observes elusive interactions of particles In 1974, a Fermilab physicist predicted a new way for ghostly particles called neutrinos to interact with matter. More than four decades later, a UChicago-led team of physicists built the world's smallest neutrino detector to observe the elusive interaction for the first time. Neutrinos are a challenge to study because their interactions with matter are so rare. Particularly elusive has been what's known as coherent elastic neutrino-nucleus scattering, which occurs when a neutrino bumps off the nucleus of an atom. The international COHERENT Collaboration, which includes physicists at UChicago, detected the scattering process by using a detector that's small and lightweight enough for a reseacher to carry. Their findings, which confirm the theory of Fermilab's Daniel Freedman, were reported Aug. 3 in the journal Science. "Why did it take 43 years to observe this interaction?" asked co-author Juan Collar, UChicago professor in physics. "What takes place is very subtle." Freedman did not see much of a chance for experimental confirmation, writing at the time: "Our suggestion may be an act of hubris, because the inevitable constraints of interaction rate, resolution and background pose grave experimental difficulties." When a neutrino bumps into the nucleus of an atom, it creates a tiny, barely measurable recoil. Making a detector out of heavy elements such as iodine, cesium or xenon dramatically increases the probability for this new mode of neutrino interaction, compared to other processes. But there's a trade-off, since the tiny nuclear recoils that result become more difficult to detect as the nucleus grows heavier. "Imagine your neutrinos are ping-pong balls striking a bowling ball. They are going to impart only a tiny extra momentum to this bowling ball," Collar said. To detect that bit of tiny recoil, Collar and colleagues figured out that a cesium iodide crystal doped with sodium was the perfect material. The discovery led the scientists to jettison the heavy, gigantic detectors common in neutrino research for one similar in size to a toaster. No gigantic lab The 4-inch-by-13-inch detector used to produce the Science results weighs only 32 pounds (14.5 kilograms). In comparison, the world's most famous neutrino observatories are equipped with thousands of tons of detector material. "You don't have to build a gigantic laboratory around it," said UChicago doctoral student Bjorn Scholz, whose thesis will contain the result reported in the Science paper. "We can now think about building other small detectors that can then be used, for example to monitor the neutrino flux in nuclear power plants. You just put a nice little detector on the outside, and you can measure it in situ." Neutrino physicists, meanwhile, are interested in using the technology to better understand the properties of the mysterious particle. "Neutrinos are one of the most mysterious particles," Collar said. "We ignore many things about them. We know they have mass, but we don't know exactly how much." Through measuring coherent elastic neutrino-nucleus scattering, physicists hope to answer such questions. The COHERENT Collaboration's Science paper, for example, imposes limits on new types of neutrino-quark interactions that have been proposed. The results also have implications in the search for Weakly Interacting Massive Particles. WIMPs are candidate particles for dark matter, which is invisible material of unknown composition that accounts for 85 percent of the mass of the universe. "What we have observed with neutrinos is the same process expected to be at play in all the WIMP detectors we have been building," Collar said. Neutrino alley The COHERENT Collaboration, which involves 90 scientists at 18 institutions, has been conducting its search for coherent neutrino scattering at the Spallation Neutron Source at Oak Ridge National Laboratory in Tennessee. The researchers installed their detectors in a basement corridor that became known as "neutrino alley." This corridor is heavily shielded by iron and concrete from the highly radioactive neutron beam target area, only 20 meters (less than 25 yards) away. This neutrino alley solved a major problem for neutrino detection: It screens out almost all neutrons generated by the Spallation Neutron Source, but neutrinos can still reach the detectors. This allows researchers to more clearly see neutrino interactions in their data. Elsewhere they would be easily drowned out by the more prominent neutron detections. The Spallation Neutron Source generates the most intense pulsed neutron beams in the world for scientific research and industrial development. In the process of generating neutrons, the SNS also produces neutrinos, though in smaller quantities. "You could use a more sophisticated type of neutrino detector, but not the right kind of neutrino source, and you wouldn't see this process," Collar said. "It was the marriage of ideal source and ideal detector that made the experiment work." Two of Collar's former graduate students are co-authors of the Science paper: Phillip Barbeau, AB'01, SB'01, PhD'09, now an assistant professor of physics at Duke University; and Nicole Fields, PhD'15, now a health physicist with the U.S. Nuclear Regulatory Commission in Chicago. The development of a compact neutrino detector brings to fruition an idea that UChicago alumnus Leo Stodolsky, SM'58, PhD'64, proposed in 1984. Stodolsky and Andrzej Drukier, both of the Max Planck Institute for Physics and Astrophysics in Germany, noted that a coherent detector would be relatively small and compact, unlike the more common neutrino detectors containing thousands of gallons of water or liquid scintillator. In their work, they predicted the arrival of future neutrino technologies made possible by the miniaturization of the detectors. Scholz, the UChicago graduate student, saluted the scientists who have worked for decades to create the technology that culminated in the detection of coherent neutrino scattering. "I cannot fathom how they must feel now that it's finally been detected, and they've achieved one of their life goals," Scholz said. "I've come in at the end of the race. We definitely have to give credit to all the tremendous work that people have done before us." [12] In search of 'sterile' neutrinos Lately, neutrinos – the tiny, nearly massless particles that many scientists study to better understand the fundamental workings of the universe – have been posing a problem for physicists. They know that these particles are produced in immense numbers by nuclear reactions such as those taking place within our sun. They also know that neutrinos don't interact very often with matter; billions of them passed through your hand in the time it took you to read this sentence. But in a host of experiments around the world, researchers are finding a deficit in the number of neutrinos they see versus what they expect to see, based on theory. And this has nothing to do with the shifting back and forth between the three flavors of neutrino that physicists also already know about. One possible explanation is that there is a fourth kind of neutrino that hasn't been detected. It's referred to as a sterile neutrino. And NIST scientists will begin looking for it next year as part of the Precision Oscillation and Spectrum Experiment (PROSPECT), a collaboration involving 68 scientists and engineers from 10 universities and four national laboratories. "This is potentially a discovery experiment," says NIST's Pieter Mumm, who is a co-founder and cospokesperson for the project, along with Karsten Heeger at Yale University and Nathaniel Bowden at Lawrence Livermore National Laboratory. Discovering a new particle would be "super exciting," he continues, because a new type of neutrino is not part of the Standard Model of physics, the wellvetted explanation for the universe as we know it. To find the new particle or definitively disprove its existence, the PROSPECT collaboration is preparing to build a first-of-its-kind detector for short-range neutrino experiments, using a nuclear reactor as the neutrino source. The work could not only shed light on new physics, but it could also give researchers a new tool to monitor and safeguard nuclear reactors. PROSPECTing for Neutrinos Unlike other neutrino experiments, which typically look at the oscillations between the three known flavors over distances of kilometers or hundreds of kilometers, PROSPECT will look at neutrino oscillations over just a few meters, the space of a small room. The distance is too short to see oscillations between the known flavors. But it is exactly the right scale for the hypothesized sterile neutrino oscillations. This setup "gives you a signature that's absolutely iron-clad," Mumm says. "If you see that variation, that characteristic oscillation, there is only one explanation for it. It has to be sterile neutrinos." The detector itself will be about 4.5 meters cubed and will be composed of an 11-by-14 array of long skinny "cells" stacked on each other [see diagram], with an expected spatial resolution of about 10 cubic centimeters. As its source for neutrinos, PROSPECT will use the High Flux Isotope Reactor at Oak Ridge Laboratory in Tennessee. The experiment will be placed as close as possible to the reactor core itself – only 7 meters (about 20 feet) away. PROSPECT will not see the sterile neutrinos directly. Rather, it will detect a particular kind of neutrino that is regularly produced in nuclear reactors: the electron-type antineutrino. To identify an electron antineutrino, the researchers will look for a particular signal in light. Each cell in the detector is filled with a scintillating material. That means that energy is converted to light, which is amplified and picked up by a pair of photomultiplier tubes on each cell. When a neutrino hits a proton in the liquid filling the cells, it creates new particles that deposit energy within the detector. These daughter particles form a signature that tells researchers that a neutrino was once there (see diagram above). "What we're actually sensing is the light emitted by the liquid scintillator," Mumm says. The signal that they are looking for is "something that looks like a positron, followed at the appropriate time [tens of microseconds, or millionths of a second] by something that looks like a neutron capture." Next Steps So far, the collaboration has created a series of prototypes, including a pair of cells built to scale, and is running simulations to validate the models they are using to separate the signal from the high backgrounds they expect. Thanks to grants from the U.S. Department of Energy and the HeisingSimons Foundation this summer, they have begun to physically build the detector. PROSPECT should answer the question of whether there are sterile neutrinos or not within three years, Mumm says. Meanwhile, the collaboration's work has some potentially game-changing spinoffs for reactor physics. For example, scientists could potentially use this technology to engineer a device to monitor reactor operations remotely. "You can imagine, at least it seems to me, that this could be a pretty powerful tool in the right circumstances," Mumm says. "You can't shield neutrinos. There's no way to spoof it." [11] As hunt for sterile neutrino continues, mystery deepens Physicists have hypothesized the existence of fundamental particles called sterile neutrinos for decades and a couple of experiments have even caught possible hints of them. However, according to new results from two major international consortia, the chances that these indications were right and that these particles actually exist are now much slimmer. In the 1990s, particle physicists at Los Alamos National Laboratory noticed something puzzling in one of their experiments. Their results disagreed with other experiments that discovered neutrino oscillations—the surprising ability of neutrinos to morph from one flavor to another—and ultimately led to last year's Nobel Prize for physics. An experiment at Fermi National Accelerator Laboratory (Fermilab) that was designed to confirm or refute the results from Los Alamos only added to the mystery by producing mixed results. To resolve the disagreement, theorists proposed the existence of an as-yet-undiscovered fundamental particle—a sterile neutrino. Physicists speculated that the hypothesized particles might hold a key to better understanding of the evolution of the universe and why it is mostly made of matter and not antimatter. Based on the Los Alamos and Fermilab results, scientists predicted a range of possible physical properties, such as mass, that sterile neutrinos could have. Several large research projects have been hunting for the elusive particles within that range. Now in this latest study, by combining results from a different experiment at Fermilab, called the Main Injector Neutrino Oscillation Search (MINOS), and another in China, called the Daya Bay Reactor Neutrino Experiment, scientists have ruled out a large portion of the range of possible properties the hypothesized particles were predicted to be hiding in. "So the plot thickens," says Karol Lang, a professor of physics at The University of Texas at Austin and co-spokesperson for the MINOS experiment. "But it's still possible that new experiments being developed at Fermilab might reveal some exciting new physics to explain these very different results." The results are being published this week as three separate letters in the journal Physical Review Letters (see links below). A team of researchers from UT Austin played many roles in producing the MINOS results, including graduate students Dung Phan, Simon De Rijck and Tom Carroll, and postdoctoral fellows Adam Schreckenberger, Will Flanagan and Paul Sail. "It is very exciting to work on one of the pioneering experiments and have such a big impact on the field," says De Rijck. Neither the MINOS nor Daya Bay results alone could be directly compared to the Los Alamos measurements, but combined, they could. "It's not common for two major neutrino experiments to work together this closely," says Adam Aurisano of the University of Cincinnati, one of the MINOS scientists. A resolution to the mystery of sterile neutrinos might come soon. Researchers in Fermilab's ShortBaseline Neutrino Program have already begun collecting data specifically targeting particles in the narrow mass range where sterile neutrinos might yet be hiding. Meanwhile, Lang and his colleagues in MINOS and Daya Bay have more data that they plan to analyze in the coming year, which might narrow the possible range of physical properties even further. "A sterile neutrino, if found, would be a game changer for particle physics," says Phan. [10] Weird quantum effects stretch across hundreds of miles In the world of quantum, infinitesimally small particles, weird and often logic-defying behaviors abound. Perhaps the strangest of these is the idea of superposition, in which objects can exist simultaneously in two or more seemingly counterintuitive states. For example, according to the laws of quantum mechanics, electrons may spin both clockwise and counter-clockwise, or be both at rest and excited, at the same time. The physicist Erwin Schrödinger highlighted some strange consequences of the idea of superposition more than 80 years ago, with a thought experiment that posed that a cat trapped in a box with a radioactive source could be in a superposition state, considered both alive and dead, according to the laws of quantum mechanics. Since then, scientists have proven that particles can indeed be in superposition, at quantum, subatomic scales. But whether such weird phenomena can be observed in our larger, everyday world is an open, actively pursued question. Now, MIT physicists have found that subatomic particles called neutrinos can be in superposition, without individual identities, when traveling hundreds of miles. Their results, to be published later this month in Physical Review Letters, represent the longest distance over which quantum mechanics has been tested to date. A subatomic journey across state lines The team analyzed data on the oscillations of neutrinos—subatomic particles that interact extremely weakly with matter, passing through our bodies by the billions per second without any effect. Neutrinos can oscillate, or change between several distinct "flavors," as they travel through the universe at close to the speed of light. The researchers obtained data from Fermilab's Main Injector Neutrino Oscillation Search, or MINOS, an experiment in which neutrinos are produced from the scattering of other accelerated, highenergy particles in a facility near Chicago and beamed to a detector in Soudan, Minnesota, 735 kilometers (456 miles) away. Although the neutrinos leave Illinois as one flavor, they may oscillate along their journey, arriving in Minnesota as a completely different flavor. The MIT team studied the distribution of neutrino flavors generated in Illinois, versus those detected in Minnesota, and found that these distributions can be explained most readily by quantum phenomena: As neutrinos sped between the reactor and detector, they were statistically most likely to be in a state of superposition, with no definite flavor or identity. What's more, the researchers found that the data was "in high tension" with more classical descriptions of how matter should behave. In particular, it was statistically unlikely that the data could be explained by any model of the sort that Einstein sought, in which objects would always embody definite properties rather than exist in superpositions. "What's fascinating is, many of us tend to think of quantum mechanics applying on small scales," says David Kaiser, the Germeshausen Professor of the History of Science and professor of physics at MIT. "But it turns out that we can't escape quantum mechanics, even when we describe processes that happen over large distances. We can't stop our quantum mechanical description even when these things leave one state and enter another, traveling hundreds of miles. I think that's breathtaking." Kaiser is a co-author on the paper, which includes MIT physics professor Joseph Formaggio, junior Talia Weiss, and former graduate student Mykola Murskyj. A flipped inequality The team analyzed the MINOS data by applying a slightly altered version of the Leggett-Garg inequality, a mathematical expression named after physicists Anthony Leggett and Anupam Garg, who derived the expression to test whether a system with two or more distinct states acts in a quantum or classical fashion. Leggett and Garg realized that the measurements of such a system, and the statistical correlations between those measurements, should be different if the system behaves according to classical versus quantum mechanical laws. "They realized you get different predictions for correlations of measurements of a single system over time, if you assume superposition versus realism," Kaiser explains, where "realism" refers to models of the Einstein type, in which particles should always exist in some definite state. Formaggio had the idea to flip the expression slightly, to apply not to repeated measurements over time but to measurements at a range of neutrino energies. In the MINOS experiment, huge numbers of neutrinos are created at various energies, where Kaiser says they then "careen through the Earth, through solid rock, and a tiny drizzle of them will be detected" 735 kilometers away. According to Formaggio's reworking of the Leggett-Garg inequality, the distribution of neutrino flavors—the type of neutrino that finally arrives at the detector—should depend on the energies at which the neutrinos were created. Furthermore, those flavor distributions should look very different if the neutrinos assumed a definite identity throughout their journey, versus if they were in superposition, with no distinct flavor. "The big world we live in" Applying their modified version of the Leggett-Garg expression to neutrino oscillations, the group predicted the distribution of neutrino flavors arriving at the detector, both if the neutrinos were behaving classically, according to an Einstein-like theory, and if they were acting in a quantum state, in superposition. When they compared both predicted distributions, they found there was virtually no overlap. More importantly, when they compared these predictions with the actual distribution of neutrino flavors observed from the MINOS experiment, they found that the data fit squarely within the predicted distribution for a quantum system, meaning that the neutrinos very likely did not have individual identities while traveling over hundreds of miles between detectors. But what if these particles truly embodied distinct flavors at each moment in time, rather than being some ghostly, neither-here-nor-there phantoms of quantum physics? What if these neutrinos behaved according to Einstein's realism-based view of the world? After all, there could be statistical flukes due to defects in instrumentation, that might still generate a distribution of neutrinos that the researchers observed. Kaiser says if that were the case and "the world truly obeyed Einstein's intuitions," the chances of such a model accounting for the observed data would be "something like one in a billion." "What gives people pause is, quantum mechanics is quantitatively precise and yet it comes with all this conceptual baggage," Kaiser says. "That's why I like tests like this: Let's let these things travel further than most people will drive on a family road trip, and watch them zoom through the big world we live in, not just the strange world of quantum mechanics, for hundreds of miles. And even then, we can't stop using quantum mechanics. We really see quantum effects persist across macroscopic distances." [9] Surprising neutrino decoherence inside supernovae Neutrinos are elementary particles known for displaying weak interactions. As a result, neutrinos passing each other in the same place hardly notice one another. Yet, neutrinos inside a supernova collectively behave differently because of their extremely high density. A new study reveals that neutrinos produced in the core of a supernova are highly localised compared to neutrinos from all other known sources. This result stems from a fresh estimate for an entity characterising these neutrinos, known as wave packets, which provide information on both their position and their momentum. These findings have just been published in EPJ C by Jörn Kersten from the University of Bergen, Norway, and his colleague Alexei Yu. Smirnov from the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The study suggests that the wave packet size is irrelevant in simpler cases. This means that the standard theory for explaining neutrino behaviour, which does not rely on wavepackets, now enjoys a more sound theoretical foundation. One of the laws governing particles at the quantum scale - called the uncertainty principle - tells us that we cannot simultaneously know a particle's position and momentum (which is the product of their mass times their velocity) with arbitrary precision. Particles like neutrinos are therefore described by a mathematical entity, called wave packets, the size of which determines the uncertainty in the neutrino's position and momentum. The authors find that neutrino wave packets in supernovae are unusually small in size. This implies that each individual neutrino displays decoherence. Kersten and Smirnov, however, show that this decoherence effect does not have any impact on the experimental measurement of the oscillation probability for each neutrino flavour; they only demonstrate this result in cases that are similar to, albeit simpler, than what happens in a supernova, where collective effects occur. In this study, the authors thus provide a theoretical motivation to the use of the standard description of supernova neutrinos, which does not rely on wave packets. Indeed, their findings suggest that collective effects are also unaffected by the neutrino wave packet size, a premise that has yet to be proven. [8] Neutrinos hint at why antimatter didn’t blow up the universe It could all have been so different. When matter first formed in the universe, our current theories suggest that it should have been accompanied by an equal amount of antimatter – a conclusion we know must be wrong, because we wouldn’t be here if it were true. Now the latest results from a pair of experiments designed to study the behaviour of neutrinos – particles that barely interact with the rest of the universe – could mean we’re starting to understand why. Neutrinos and their antimatter counterparts, antineutrinos, each come in three types, or flavours: electron, muon and tau. Several experiments have found that neutrinos can spontaneously switch between these flavours, a phenomenon called oscillating. The T2K experiment in Japan watches for these oscillations as neutrinos travel between the J-PARC accelerator in Tokai and the Super-Kamiokande neutrino detector in Kamioka, 295 kilometres away. It began operating in February 2010, but had to shut down for several years after Japan was rocked by a magnitude-9 earthquake in 2011. Puff of radiation In 2013, the team announced that 28 of the muon neutrinos that took off from J-PARC had become electron neutrinos by the time they reached Super-Kamiokande, the first true confirmation that the metamorphosis was happening. They then ran the experiment with muon antineutrinos, to see if there was a difference between how the ordinary particles and their antimatter counterparts oscillate. An idea called charge-parity (CP) symmetry holds that these rates should be the same. CP symmetry is the notion that physics would remain basically unchanged if you replaced all particles with their respective antiparticles. It appears to hold true for nearly all particle interactions, and implies that the universe should have produced the same amount of matter and antimatter in the big bang.Matter and antimatter destroy one another, so if CP symmetry holds, both should have mostly vanished in a puff of radiation early on in the universe’s history, well before matter was able to congeal into solid stuff. That’s clearly not what happened, but we don’t know why. Any deviation from CP symmetry we observe could help explain this discrepancy. “We know in order to create more matter than antimatter in the universe, you need a process that violates CP symmetry,” says Patricia Vahle, who works on NoVA, a similar experiment to T2K that sends neutrinos between Illinois and Minnesota. “So we’re going out and looking for any process that can violate this CP symmetry.” Flavour changers We already know of one: the interactions of different kinds of quarks, the constituents of protons and neutrons in atoms. But their difference is not great enough to explain why matter dominated so completely in the modern universe. Neutrino oscillations are another promising place to look for deviations. This morning at the Neutrino conference in London, UK, we got our first signs of such deviations. Hirohisa Tanaka of the University of Toronto, Canada, reported the latest results from T2K. They have now seen 32 muon neutrinos morphing into the electron flavour, compared to just 4 muon antineutrinos becoming the anti-electron variety. This is more matter and less antimatter than they expected to see, assuming CP symmetry holds. Although the number of detections in each experiment is small, the difference is enough to rule out CP symmetry holding at the 2 sigma level – in other words, there is only around a 5 per cent chance that T2K would see such differences if CP symmetry is preserved in this process. Particle physicists normally wait until things reach the 3 sigma level before getting excited, and won’t consider it a discovery until 5 sigma, so it’s early days for neutrinos breaking CP symmetry. But at the same conference, Vahle presented the latest results from NoVA that revealed the two experiments were in broad agreement about the possibility. The extent of CP violation rests on a key parameter called delta-CP, which ranges from 0 to 2π. Both teams found that their results were best explained by setting the value equal to 1.5π. “Their data really does prefer the same value that T2K does,” says Asher Kaboth, who works on T2K. “All of the preferences for the delta-CP stuff are pointing in the same direction.” NoVA plans to run its own antineutrino experiments next year, which will help firm up the results, and both teams are continuing to gather more data. It’s too soon to say definitively, but one of the mysteries of why we are here could be on the road to getting solved. [7] What the universe's most elusive particles can tell us about the universe's most energetic objects In 2012, a tiny flash of light was detected deep beneath the Antarctic ice. A burst of neutrinos was responsible, and the flash of light was their calling card. It might not sound momentous, but the flash could give us tantalising insights into one of the most energetic objects in the distant universe. The light was triggered by the universe's most elusive particles when they made contact with a remarkable detector, appropriately called IceCube, which was built for the very purpose of capturing rare events such as this. The team of international researchers now suspects the event may have originated from a quasar, which is the active nucleus of a galaxy billions of light-years away. The flash also potentially opens up a new era of neutrino astrophysics and may help unravel the mystery of neutrino production in the universe. The antisocial particle that came in from the cold Neutrinos are elementary particles and one of the smallest building blocks of the universe. Despite being one of the most abundant and energetic particles, neutrinos have a reputation of being notoriously hard to detect. This is because they very rarely interact with normal matter. In fact, billions of them pass through your body every minute without even causing a tickle. What the universe's most elusive particles can tell us about the universe's most energetic objects There’s a lot more of the IceCube neutrino detector below the ice. Credit: Erik Beiser, IceCube/NSF So how do you find such an antisocial particle? It might not look it from the frosty surface of Antarctica, but Ice Cube is one of the world's largest telescopes, and the largest for detecting neutrinos. IceCube occupies a cubic kilometre of clear ice, which provides the best medium for thousands of sensors to capture that elusive burst of light created when a high energy neutrino collides with an ice particle. Although the probability of a collision is minuscule, there are so many neutrinos that pass through the detector that eventually some will interact with the ice. The trick then is to determine where the neutrinos originated. Neutrinos are produced by the nuclear reactions going on at the centre of stars and in other highly energetic cosmic processes. So when trying to find origin of the 2012 neutrino burst, Professor Sergei Gulyaev, the director of Auckland University of Technology's Institute for Radio Astronomy and Space Research told The Conversation that there was no shortage of candidates. The sky was literally the limit. "Out of millions of astronomical objects, which one was responsible?" Nucleus of a galaxy A network of New Zealand, Australian and African radio telescopes searched the skies for what might have triggered the 2012 flash. But one candidate stood out. Radio astronomers were able to create an image of a distant object that appeared to change dramatically after the neutrino burst was registered in South Pole. What the universe's most elusive particles can tell us about the universe's most energetic objects The IceCube detector contains 5,160 individual sensors that go down to a depth of nearly 2.5 kilometres beneath the ice. Credit: IceCube Collaboration From this, they decided that the most likely source of the neutrinos was a quasar, called PKS 1424418, located 9.1 billion light years away – nearly at the edge of the visible universe. A quasar is the active nucleus of a primordial galaxy with a supermassive black hole at its core. "We knew before that huge fluxes of very energetic particles came from space. We call them 'cosmic rays'. Neutrinos are part of them. But we had no idea which astronomical objects are responsible for this." Gulyaev emphasised that they had to be cautious before drawing any conclusions about the source of the neutrinos. "We were very careful, but combining radio astronomical and gamma-ray observations made by NASA's Fermi gamma-ray space telescope, we now know where or what it is. Given the huge increase in energy, shape change and activity, we are 95% sure that a quasar was responsible for the event registered by IceCube." Gulyaev added that this particular quasar was active while the universe was very young. "Quasars are like dinosaurs. They became extinct a long time ago," said Gulyaev. "But because astronomy is like a time machine, we were able to study this quasar." The study may also open a new window into the distant universe. Whereas most astronomy is conducted by studying electromagnetic radiation, such as light or radio waves, these can be obscured or distorted as they travel through space. But because neutrinos pass through most matter, and aren't influenced by magnetic fields, they can pass through vast stretches of the cosmos uninterrupted. If we can detect them reliably, we might be able to observe things we can't normally see. An exciting problem Professor Ron Ekers, an astrophysicist from CSIRO, said the study presents tantalising possibilities of an extragalatic origin of the high energy neutrino burst. However, the true test of time will be if the model can eventually predict future detections alongside more precise measurements of neutrino positions that would be possible in the future. Ekers said that although the model presents a possible origin, a crucial step would be to increase the level of accuracy in neutrino detection instruments to more precisely pinpoint and narrow down possible sources. "Current position errors for these neutrinos are quite large and there are many possible objects which could be the source." Ekers added that both IceCube and the Mediterranean Neutrino Array (KM3NeT) have future plans to greatly improve positional accuracy to fulfil that need. "Finding out where the high energy neutrinos come from is one of the most exciting problems in astrophysics today. Now we have a possible identification we desperately need to improve the directional accuracy of the neutrino detections. " [6] Neutrinos: Ghosts of the Universe Why, after millions of years of steadily lighting the cold darkness, does a supergiant star suddenly explode in a blinding blaze of glory brighter than 100 billion stars? What exotic objects in deep space are firing out particles at by far the highest energies in the universe? And perhaps most mind-bending, why does the universe contain any matter at all? These mysteries have vexed astrophysicists and particle physicists for decades. The key to solving all three deep conundrums is itself one of the greatest enigmas of physics: the neutrino. The universe is awash in these peculiar, nearly massless, subatomic particles. Created in tremendous numbers right after the Big Bang, and constantly churned out in stars and other places by radioactive decay and other reactions, trillions of these ghostly particles sail right through stars and planets, including our own. Carrying no electrical charge, neutrinos are attracted neither to protons nor electrons, so they don’t interact with electromagnetic fields. They also don’t feel a powerful force that operates on tiny scales, known simply as the strong force, which binds protons and neutrons together in an atom’s nucleus. Neutrinos are more aloof than supermodels, rarely interacting meaningfully with one another or with anything else in the universe. Paradoxically, it is their disengaged quality that earns them a crucial role both in the workings of the universe and in revealing some of its greatest secrets. Neutrino physics is entering a golden age. As part of one experiment, neutrinos have recently opened a new window on high-energy sources in deep space, such as black holes spewing out particles in beams trillions of miles long. Another astronomy experiment deep underground in a Japanese mine will use neutrinos to learn the average temperature and energy of ancient supernovae to better understand their typical behavior. And physicists are using computer modeling to close in on the neutrino’s critical role in triggering the kind of supernovae that distribute essential elements like oxygen and nitrogen. Beyond expanding the role of neutrinos in astronomy and uncovering their role in astrophysics, physicists are still trying to discover some of the neutrino’s basic properties. Some researchers, for instance, are trying to pin down the particle’s possible masses. That fundamental information would influence theories that explain the masses of other particles. By determining yet another elusive fundamental property of neutrinos, researchers also hope to answer one of theoretical physics’s great riddles: why all the matter and antimatter created by the Big Bang didn’t cancel each other out and leave nothing but energy. At the dawn of the universe, for every particle of matter, such as an electron, there was an anti-electron; for every quark (a fundamental constituent of matter), there was an antiquark, explains physicist Chang Kee Jung of Stony Brook University. When these opposites meet, they should annihilate each other, creating pure energy. So why is any matter left? The most plausible solution, leading physicists like Jung say, hinges on the theory that today’s neutrinos, which have barely any mass, once had superheavy partners. These neutrino cousins, 100 trillion times more massive than a proton, formed in the tremendous heat that existed right after the Big Bang. They had the special androgynous ability to decay into either matter or antimatter counterparts. One such overweight particle might have decayed into a neutrino plus some other particle — like an electron, for instance — while another superheavy neutrino might have decayed into an antineutrino and another particle. For this theory to explain why matter exists, those early superheavy neutrinos would have had to decay more frequently into particles than antiparticles. Physicists at neutrino detectors such as NOvA in Minnesota, in addition to trying to determine the masses of the neutrino, are studying whether today’s lighter neutrinos switch from one type (or “flavor”) to another at a different rate than antineutrinos. The same theory that could explain this behavior in today’s light neutrinos could also explain the inclinations of superheavy neutrinos at the dawn of time. If the superheavy neutrino theory is correct, then these primordial particles are the “supreme ancestor” from which every particle in the cosmos descended. Neutrino-related discoveries have already earned three Nobel prizes, and the path-breaking experiments underway could well earn more tickets to Stockholm. The seemingly superfluous neutrino couldn’t be more essential to our understanding of the cosmos, or less concerned with its profound importance. The Ice Telescope Cometh Computers at the IceCube Laboratory at the Amundsen-Scott South Pole Station collect raw data and analyze results from the underground neutrino detector. Scientists who want to detect neutrinos must build their detectors deep underground or underwater to filter out the cosmic rays that constantly bombard Earth. (Neutrinos travel through matter, regardless of how dense.) Francis Halzen, a physicist at the University of Wisconsin-Madison, realized decades ago that Antarctica was an ideal spot because the ice was thick enough to bury thousands of light sensors more than a mile deep. When a neutrino chances to slam into an atomic nucleus in the ice, an electron or muon (a heavier cousin of the electron) is created, releasing a trace of light. That trace of light can be picked up by IceCube, an underground telescope and particle detector at the South Pole. Halzen is one of nearly 250 people involved with the project. In May 2012, IceCube physicists discovered the light footprints of two neutrinos with an incredible 1,000 times more energy than any neutrino ever detected before on Earth. Christened Bert and Ernie after the Sesame Street characters, they spurred IceCube scientists to re-examine the data at that energy level. Sure enough, they found 26 more high-energy neutrinos. When the scientists looked at more recent data through May 2013, they found nine more high-energy neutrinos, one of which had the energy of Bert and Ernie combined. “It’s named Big Bird, of course,” says Halzen. Some neutrinos almost certainly hail from beyond our galaxy, and they could help solve a centuryold mystery on the source of incredibly high-energy cosmic rays. That source also is thought to produce high-energy neutrinos. Some possible scenarios: incredibly massive black holes erupting in jets of matter, galaxies colliding or star-producing factories known as starburst galaxies. “IceCube is finally opening a new window on the universe,” says physicist John Beacom of Ohio State University. “All these years we have been doing astronomy with light (not just visible light), we have been missing a big part of the action.” Neutrino Mysteries Shape-Shifting Neutrinos are notorious shape-shifters. Each one is born as one of three types, or flavors — electron, muon and tau — but they can change flavor in a few thousandths of a second as they travel, as if they can’t make up their mind what to be. Neutrinos, like other subatomic particles, sometimes behave like waves. But as the neutrino travels, the flavor waves combine in different ways. Sometimes the combination forms what is mostly an electron neutrino and sometimes mostly a muon neutrino. Because neutrinos are quantum particles, and by definition weird, they are not one single flavor at a time, but rather always a mixture of flavors. On the very, very rare occasion that a neutrino interacts with another particle, if the reaction appears to produce an electron, then the neutrino was an electron flavor in its final moments; if it produces a muon, the neutrino was muon-flavored. It’s as if the shy neutrino’s identity crisis can only be resolved when it finally interacts with another particle. Heavyweight Competition Physicists hope to use neutrinos’ strange shape-shifting behavior to unlock several mysteries. Scientists know the mass of every other fundamental particle, such as the electron, but the neutrino — at least a million times as light as the electron — is far more elusive because of its transformative ways. The discovery of neutrino masses would influence the fundamental theory of how particles and forces interact, the so-called standard model of particle physics. Physicists already know the theory is incomplete because it incorrectly predicts neutrinos have no mass. “It may help us to better understand the reasons behind the masses of all particles,” says William Louis of Los Alamos National Laboratory. “A jigsaw puzzle is much easier to put together once all of the pieces are available.” The difficulty in pinning down neutrino masses lies in the Heisenberg uncertainty principle, a cornerstone of quantum physics. It states that certain properties of subatomic particles are linked such that the more precisely you know one, the less precisely you can know the other. For instance, if you know exactly where a particle is, then you can’t know its momentum. And once you’ve pinned down the particle’s momentum, you can’t absolutely know its location. A neutrino’s flavor and mass are linked in a similar way, says Indiana University physicist Mark Messier. You can’t know both at the same time. For that reason, he says, “We always measure some combination of masses. … It does not even make sense to ask what the mass is for a single flavor of neutrino.” As far as scientists can tell, each neutrino is a combination of three masses, but they can’t learn that combination without taking a measurement. Two of those masses are likely to identify as electron neutrinos a significant portion of the time, and one mass only infrequently comes up as electron neutrino, says Messier. Physicists are not sure if the greatest, or heaviest, of the three masses is most likely to be an electron neutrino or least likely to be an electron neutrino. When Lefties Turn Right All matter has a mirror image, called antimatter. For an electron, which has a negative charge, the antimatter twin — the positron — is identical except that it has a positive charge. If matter meets antimatter, they destroy each other in a burst of energy. For each of the three flavors of neutrino, there is also a corresponding antineutrino called, sensibly enough, electron antineutrino, muon antineutrino and tau antineutrino. Because neutrinos are neutral, their antiparticles cannot have opposite charges. Instead, their “spin” is reversed. (Neutrinos are too small to really spin like a planet; the term spin refers to a property that is in some ways equivalent to spin.) Neutrinos are “left-handed” — they always spin to the left, relative to their direction of motion. Antineutrinos are “right-handed.” The eccentric Sicilian theorist Ettore Marjorana suggested that since neutrinos are neutral, they may be their own antiparticle — meaning that under certain circumstances, a neutrino could act like an antineutrino. If that were true, it would satisfy one necessary condition for the supreme ancestor neutrino theory that explains why we and all matter in the universe exist. Cracked Mirror? If you apply the laws of physics to antimatter, everything works out the same, just reversed. A magnetic field would push on an electron and a positron with exactly the same force: For example, if the electron were pushed right, the positron would be pushed left. Physicists hope that neutrinos don’t necessarily follow this mirror effect, and that they may once again be the oddballs that lead to a new understanding of nature. In experiments in the U.S. and Japan, researchers are trying to determine if the metamorphosis of neutrinos into different flavors happens at a different rate than the antineutrino transformations. So rather than, say, a 10 percent chance of an electron neutrino turning into a muon neutrino, for example, physicists wonder if the odds are lower that an electron antineutrino turns into a muon antineutrino. They’ve seen precedents for such “asymmetrical” behavior in a few other particles, and certain theories predict that behavior in neutrinos. If neutrinos do indeed transform into other flavors at a different rate from antineutrinos, it’s likely that this matter/antimatter difference in neutrinos was present in their superheavy ancestors at the dawn of time, too. Seeing Stars Astrophysicist Hans-Thomas Janka and his team use a bank of supercomputers to create 3-D models of the heat that builds in a neutrino-driven explosion of a star. Leonhard Scheck and H.-Thomas Janka (Max Planck Institute for Astrophysics) Somewhere in the universe, at least once a second, a massive star goes supernova, blowing to smithereens with the intensity of an entire galaxy’s worth of shining stars. After 50 years of investigation, no one knows exactly why supernovae occur. But to astrophysicist Hans-Thomas Janka, it’s clear the neutrino is a major culprit in this mystery. Working from the Max Planck Institute for Astrophysics in Munich, Janka has enlisted dozens of the world’s most powerful computers on a decades-long quest to understand the incredibly complex mechanism of a supernova. Advances in computing power and physics have helped him build sophisticated models, spun from hundreds of thousands of lines of computer code, that capture the nuances of the stars’ shape while taking into account everything from stars’ rotation and nuclear reactions to Einstein’s theory of gravity. Now, for the first time, Janka’s latest models fully describe the behavior of neutrinos under the hellish conditions of a star’s demise. In 1982, James Wilson of Lawrence Livermore National Laboratory first showed how neutrinos might trigger the explosion. Wilson knew that when a massive star burns up the last of its fuel after some 10 million years, its core rapidly implodes, pulling all of the star’s matter inward. The implosion begins to turn into an explosion, and a shock wave forms. But within a few thousandths of a second, it stops cold. Then something causes the shock wave to “revive” and trigger the explosion, leaving behind a dense neutron star. Through rudimentary computer modeling, Wilson discovered that that something was neutrinos, generated in copious amounts — on the order of 1 followed by 58 zeroes — when the electrons and protons in the core turn into neutrons. Because those neutrons are packed so tightly — a teaspoon would weigh 100 million tons — the neutrinos would get trapped there, bouncing off and interacting with the other particles (mostly neutrons, but some protons and electrons) trillions of times. The neutrinos would be delayed in the core only for a second, but Wilson suspected that enough heat would be generated to trigger the supernova explosion. Limited by the era’s computers and understanding of physics, Wilson’s model relied on simplifications — such as the star being a perfect sphere — and incorrect assumptions about the behavior of very dense matter and how neutrinos move from the core’s interior to the crucial outer parts where the heating of the shock wave occurs. The model did not work. Janka learned about Wilson’s model four years later, as a graduate student at Technical University Munich. He thought the theory sounded plausible and developed a new way to describe neutrino physics in supernovae, working on newly available $25 million supercomputers at the Max Planck Institute, one of the few places in Europe where the computers were available for unclassified research. Janka seemed to work nonstop, his ferocious drive coexisting with a persistent fear: Because he was one of only a handful working in what was then a limited field of study, Janka worried that by the time he completed his doctorate, he’d be a 30-something with few job prospects. But the heavens intervened. In 1987, the first supernova visible to the naked eye since 1604 appeared in the Large Magellanic Cloud, our closest neighboring galaxy. Of the trillions of neutrinos the blast emitted, detectors on Earth captured 24, suddenly inaugurating a new field of particle astrophysics. “It was an initial boost that affected all my career,” says Janka. “That was the reason that a big neutrino astrophysics research program was started in Munich and that I got a permanent job there in 1995.” That 1987 supernova confirmed the basic picture of a collapsed core of a massive star spewing an enormous blast of neutrinos. Janka eagerly started building computer models, but like Wilson, he had to assume the star was spherical, an oversimplification dictated by the high costs of computing power. When Janka ran the models, the star did not explode. Over the next decade, he collaborated with Ewald Mueller of the Max Planck Institute for Astrophysics to create more complex models. They fleshed out how neutrinos interact and how they leak out of the core of a collapsed star. “He built up his expertise very systematically as he attacked different pieces of the puzzle,” says physicist Thomas Baumgarte of Bowdoin College, who has known Janka for about 20 years. By 2005, Janka had developed more sophisticated code for a model that more accurately represented the shape of the star, though it was still an approximation. In this model, called a twodimensional type, Janka refined the physics of how neutrinos moved in connection with the flow of the other matter in the star. But he lacked computer power to test the model. Then in 2006, fortune struck again. The managing director of the Max Planck Institute asked Janka if he could do anything with 700,000 euros, at the time equal to $875,000. Janka bought 96 1.282gigahertz processors, the fastest available. “The computers worked on the problem continuously for the next three years to get one second of evolution — from supernova core collapse to 750 milliseconds after the neutron star at the center begins to form,” Janka says. This work led to the first sophisticated 2-D model of a giant star in extremis — and this time, the model star exploded. Janka’s group had worked out highly complex physical equations to describe neutrino interactions and how the gas of the star flows and bubbles, turning Wilson’s theoretical vision into a far more detailed and sophisticated simulation. Since Janka simplified the star’s shape, his model didn’t completely solve the mystery. His group is now incorporating what’s been learned about neutrino interactions into new, state-of-the-art models that don’t idealize a star’s shape. At Janka’s disposal is a fair share of the processors of two huge supercomputers, one in Paris and one in Munich, with the power of 32,000 workstations: Together, they can calculate more than 100 trillion operations per second. But Janka finds himself once again at the outer limit of computing power. These 3-D models, he says, are in their infancy and don’t yet explode. Janka’s group recently won a five-year, $4 million grant to give the 3-D model higher resolution and to push the simulation “backward in time, and also forward, linking the model to observed supernova remnants,” he says. Janka “is doing the leading work” in this highly competitive field, says supernova pioneer Stanford Woosley of the University of California, Santa Cruz. Groups at Princeton University and Oak Ridge National Laboratory, he says, are also within reach. “Victory will go to the one who gets the 3-D model of a 15-solar-mass star [the size of 15 suns] to explode with the right energy,” says Woosley, since that’s the size of star that can synthesize elements important for life. That’s ultimately the allure of these fiery enigmas. “The oxygen we breathe, the iron in our blood, the carbon in plants, the silicon in the sand — all the matter that makes up you and the Earth is made and distributed by supernovae,” Janka says. We are all star descendants, forged from matter created hundreds to thousands of light-years away in a titanic explosion where a reticent ghost particle finally, violently, made its presence felt. Double Trouble Several major experiments around the world are designed to catch the elusive neutrino in the act of not showing up. In a radioactive metamorphosis called single beta decay, a neutron (a neutral particle) in the nucleus of an unstable atom spontaneously turns into a proton (a positive particle) and emits an electron and an antineutrino — the antimatter twin of a neutrino. In double beta decay, the interaction is doubled: Two neutrons simultaneously decay into two protons. However, instead of producing two electrons and two antineutrinos, as one might expect, physicists such as Giorgio Gratta of Stanford University suspect that in some instances, no antineutrinos are emitted. That can happen only if neutrinos are their own antiparticle, in which case an antineutrino would be emitted by a neutron and then — presto! — absorbed as a neutrino by a neutron. The discovery of the neutrino’s double anti-identity, although expected by many physicists, would contradict the standard model of particle physics, the current mainstream understanding of the way particles and fundamental forces behave, necessitating a paradigm-shifting extension. If the decay of an unstable atom produces two electrons but no antineutrinos, physicists will have found decisive evidence for this elusive, eccentric behavior. Experiments in the United States, such as the Enriched Xenon Observatory 200 (EXO-200) in New Mexico, as well as ones in Japan and Europe, are trying to catch a glimpse of this fantastically rare interaction. “People have been trying to find this critical decay for a long time,” says Gratta, the lead scientist at EXO. The Super-K's detector houses 13,000 photomultipliers that help detect the smallest trace of light from neutrino interactions. Built in a zinc mine near Hida, Japan, the Super-Kamiokande (Super-K) experiment has been searching for telltale flashes of light in a 50,000-ton tank of the purest water on Earth since 1996. When a low-energy neutrino or antineutrino from a supernova collides with a water molecule in the tank, the resulting light signal is recorded by about 100 of 13,000 photomultipliers, ultrasensitive light-detecting devices that turn a tiny flash of light into a larger recordable burst of electricity. But sometimes, false positives occur: Radioactive decays in the detector also create light, as do neutrinos produced in the atmosphere when they collide with the water. Now, Super-K scientists plan to silence the false positives using a method suggested by physicists John Beacom and Mark Vagins that focuses on the antineutrinos that supernovae produce. They’ll add 50 tons of the rare earth metal gadolinium to the water in Super-K, allowing them to tell the difference between encounters with antineutrinos and other light-emitting pretenders. When an antineutrino knocks into a proton in the Super-K water, that proton turns into a neutron and instantly emits a positively charged particle that gives off blue light as it rapidly moves through the water. The gadolinium would capture the neutron about 20 microseconds after it’s created, taking it into its own nucleus and leading to the immediate burst of gamma rays. The photomultipliers capture the whole sequence. No other particle interaction would lead to that onetwo “heartbeat.” The light in each beat reveals two things: The first flash indicates the energy of the antineutrino; the second confirms that the particle was an antineutrino. “Currently, Super-Kamiokande can detect neutrinos from supernova explosions anywhere in our own Milky Way galaxy,” says Vagins, of the Kavli Institute for the Physics and Mathematics of the Universe. “Adding gadolinium will make the detector vastly more sensitive, which will enable SuperK to begin collecting antineutrinos from supernova explosions anywhere within half the known universe.” That would include lower-energy, harder-to-detect antineutrinos created by massive stars that exploded billions of years ago. Adding gadolinium would “allow us to determine the total energy and temperature of an average supernova, two key inputs in all kinds of cosmological and stellar evolution models,” says Vagins. Called GADZOOKS! — for Gadolinium Antineutrino Detector Zealously Outperforming Old Kamiokande, Super! — the enriched detector, expected to go online in 2017, will also have a better chance of catching the birth of a black hole in the remnants of an exploding star. Neutrinos can’t escape from black holes, and the supersensitive Super-K will be able to detect a telltale stream of neutrinos that suddenly shuts down. “Super-K would be able to see a black hole form minutes or even hours after the initial core collapse. … Without gadolinium, it will be limited to 10 seconds or so,” says Vagins. Flying High The balloon-borne experiment ANITA (Antarctic Impulsive Transient Antenna) heads to the heavens at the end of this year. It will try to detect the sources of the highest-energy neutrinos in the universe. These neutrinos are thought to result from ultrahigh-energy cosmic rays crashing into the low-energy invisible photons left over from the Big Bang that still suffuse all of space. What sort of phenomenon creates and launches the cosmic ray sources of these neutrinos? Perhaps a hypernova — a “supernova on steroids” — or a rapidly spinning black hole or, more likely yet, a supermassive black hole, says physicist Peter Gorham of the University of Hawaii, the project’s lead investigator. The NASA-funded balloon will be 35,000 meters over the Antarctic ice cap. Circling the South Pole, ANITA’s antennas will scan a million cubic kilometers of ice at a time, looking for the telltale radio waves emitted when an ultrahigh-energy neutrino hits a nucleus in ice. It will be ANITA’s third voyage. Last year, physicists began shooting 150 trillion neutrinos per second from the Fermi National Accelerator Laboratory, west of Chicago, to a detector in Minnesota — a 503-mile underground trip that will take them just 2.7 milliseconds. Called the NuMI Off-axis Electron Neutrino Appearance experiment, or NOvA, the project relies on a 15,400-ton detector containing 3 million gallons of a liquid solution with a material known as a scintillator. Scintillators absorb the energy of incoming particles and emit that energy in the form of light. Of the torrent of particles Fermilab sends, only about 10 neutrinos interact with the scintillator each week. But the result will be a light signature that reveals the neutrino’s flavor and energy. More than 200 scientists, engineers and technicians helped design and build Fermilab’s flagship experiment over the past 12 years. Physicist Mark Messier of Indiana University, one of the experiment’s co-leads, says NOvA “has the best shot at taking the next big step in uncovering new properties of neutrinos.” One of NOvA’s goals, Messier says, is to help figure out which of the three mixes of neutrino flavors is heaviest and which is lightest — their so-called mass ordering. Mass is a fundamental but mysterious property of neutrinos that affects many physics theories because the origin of neutrino masses is still unknown. The NOvA neutrinos will start off as muon flavor, but then do their typical transforming act into electron neutrinos. Electron-flavor neutrinos are special because they can interact with the Earth: They alone can meaningfully interact with electrons in atoms. The key for NOvA is that the greater the mass of the electron neutrino flavor, the more likely the beam of neutrinos will interact with the hundreds of miles of matter they cross on the way to the detector. “Because the electrons in the Earth ‘drag’ on the electron neutrinos, that effectively gives the electron neutrinos some additional mass,” says Messier. That effect determines the neutrino’s transformation rate. If electron neutrinos tend to have the lightest mix of masses, the added heaviness from its earthly interactions would make it change to muon neutrinos at a higher rate because it would “mix” or “overlap more” with the muon masses, as Messier puts it, referring to the wavelike behavior of these particles. On the other hand, if the electron neutrinos contain the heaviest masses, then the additional Earth-induced mass would make them mix less with those of the other two neutrino flavors. NOvA is also doing the experiment with antineutrinos, which offer a valuable comparison, Messier says. And it might give a hint of whether neutrinos and antineutrinos morph at different rates, yet another unusual neutrino property that would not be totally unexpected. Neutrino Gold 1988: Leon Lederman, Melvin Schwartz and Jack Steinberger win the Nobel Prize in Physics for developing a way to generate beams of neutrinos in a particle collider and for discovering the muon neutrino. 1995: Frederick Reines wins a Nobel for detecting neutrinos for the first time in a 1953 experiment dubbed Project Poltergeist. Clyde Cowan, his collaborator, had died 21 years earlier. 2002: Ray Davis earns the prize for detecting neutrinos from the sun using 600 tons of dry-cleaning fluid in a giant underground tank in South Dakota. Davis shared the Nobel with Masatoshi Koshiba, who used the gigantic Kamiokande detector in Japan to confirm Davis’ results and to capture neutrinos from a supernova that exploded in a neighboring galaxy. [5] Possible new particle hints that universe may not be left-handed Mirroring the universe (Image: Claudia Marcelloni/CERN) Like your hands, some fundamental particles are different from their mirror images, and so have an intrinsic handedness or “chirality”. But some particles only seem to come in one of the two handedness options, leading to what’s called “left-right symmetry breaking”. In particular, W bosons, which carry the weak nuclear force, are supposed to come only in lefthanded varieties. The debris from smashing protons at the LHC has revealed evidence of unexpected right-handed bosons. After finding the Higgs boson in 2012, the collider shut down for upgrades, allowing collisions to resume at higher energies earlier this year. At two of the LHC’s experiments, the latest results appear to contain four novel signals. Together, they could hint at a W-boson-like particle, the W’, with a mass of about 2 teraelectronvolts. If confirmed, it would be the first boson discovered since the Higgs. The find could reveal how to extend the successful but frustratingly incomplete standard model of particle physics, in ways that could explain the nature of dark matter and why there is so little antimatter in the universe. The strongest signal is an excess of particles seen by the ATLAS experiment (arxiv.org/abs/1506.00962), at a statistical significance of 3.4 sigma. This falls short of the 5 sigma regarded as proof of existence (see “Particle-spotting at the LHC“), but physicists are intrigued because three other unexpected signals at the independent CMS experiment could point to the same thing. “The big question is whether there might be some connection between these,” says Bogdan Dobrescu at Fermilab in Chicago. In a paper posted online last month, Dobrescu and Zhen Liu, also at Fermilab, showed how the signals could fit naturally into modified versions of left-right symmetric models (arxiv.org/abs/1507.01923). They restore left-right symmetry by introducing a suite of exotic particles, of which this possible W’ particle is one. Another way to fit the right-handed W’ into a bigger theory was proposed last week by Bhupal Dev at the University of Manchester, UK, and Rabindra Mohapatra at the University of Maryland. They invoke just a few novel particles, then restore left-right symmetry by giving just one of them special properties (arxiv.org/abs/1508.02277). Some theorists have proposed that these exotic particles instead hint that the Higgs boson is not fundamental particle. Instead, it could be a composite, and some of its constituents would account for the observed signals. “In my opinion, the most plausible explanation is in the context of composite Higgs models,” says Adam Falkowski at CERN. “If this scenario is true, that would mean there are new symmetries and new forces just around the corner.” “If the Higgs is really a composite particle, that would mean new forces just around the corner” The next step is for the existence of the right-handed W’ boson to be confirmed or ruled out. Dobrescu says that should be possible by October this year. But testing the broader theories could take a couple of years. Other LHC anomalies have disappeared once more data became available. That could happen again, but Raymond Volkas at the University of Melbourne, Australia, says this one is more interesting. “The fact that the data hint at a very sensible and well-motivated standard model extension that has been studied for decades perhaps is reason to take this one a bit more seriously,” he says. [4] Asymmetry in the interference occurrences of oscillators The asymmetrical configurations are stable objects of the real physical world, because they cannot annihilate. One of the most obvious asymmetry is the proton – electron mass rate Mp = 1840 Me while they have equal charge. We explain this fact by the strong interaction of the proton, but how remember it his strong interaction ability for example in the H – atom where are only electromagnetic interactions among proton and electron. This gives us the idea to origin the mass of proton from the electromagnetic interactions by the way interference occurrences of oscillators. The uncertainty relation of Heisenberg makes sure that the particles are oscillating. The resultant intensity due to n equally spaced oscillators, all of equal amplitude but different from one another in phase, either because they are driven differently in phase or because we are looking at them an angle such that there is a difference in time delay: (1) I = I0 sin2 n φ/2 / sin2 φ/2 If φ is infinitesimal so that sinφ = φ than (2) ι = n2 ι0 This gives us the idea of (3) Mp = n2 Me Figure 1.) A linear array of n equal oscillators There is an important feature about formula (1) which is that if the angle φ is increased by the multiple of 2π it makes no difference to the formula. So (4) d sin θ = m λ and we get m-order beam if λ less than d. [6] If d less than λ we get only zero-order one centered at θ = 0. Of course, there is also a beam in the opposite direction. The right chooses of d and λ we can ensure the conservation of charge. For example (5) 2 (m+1) = n Where 2(m+1) = Np number of protons and n = Ne number of electrons. In this way we can see the H2 molecules so that 2n electrons of n radiate to 4(m+1) protons, because de > λe for electrons, while the two protons of one H2 molecule radiate to two electrons of them, because of de < λe for this two protons. To support this idea we can turn to the Planck distribution law, that is equal with the Bose – Einstein statistics. Spontaneously broken symmetry in the Planck distribution law The Planck distribution law is temperature dependent and it should be true locally and globally. I think that Einstein's energy-matter equivalence means some kind of existence of electromagnetic oscillations enabled by the temperature, creating the different matter formulas, atoms molecules, crystals, dark matter and energy. Max Planck found for the black body radiation As a function of wavelength (λ), Planck's law is written as: Figure 2. The distribution law for different T temperatures We see there are two different λ1 and λ2 for each T and intensity, so we can find between them a d so that λ1 < d < λ2. We have many possibilities for such asymmetrical reflections, so we have many stable oscillator configurations for any T temperature with equal exchange of intensity by radiation. All of these configurations can exist together. At the λmax is the annihilation point where the configurations are symmetrical. The λmax is changing by the Wien's displacement law in many textbooks. (7) where λmax is the peak wavelength, T is the absolute temperature of the black body, and b is a constant of proportionality called Wien's displacement constant, equal to 2.8977685(51)×10−3 m·K (2002 CODATA recommended value). By the changing of T the asymmetrical configurations are changing too. The structure of the proton We must move to the higher T temperature if we want look into the nucleus or nucleon arrive to d<10-13 cm. If an electron with λe < d move across the proton then by (5) 2 (m+1) = n with m = 0 we get n = 2 so we need two particles with negative and two particles with positive charges. If the proton can fraction to three parts, two with positive and one with negative charges, then the reflection of oscillators are right. Because this very strange reflection where one part of the proton with the electron together on the same side of the reflection, the all parts of the proton must be quasi lepton so d > λq. One way dividing the proton to three parts is, dividing his oscillation by the three direction of the space. We can order 1/3 e charge to each coordinates and 2/3 e charge to one plane oscillation, because the charge is scalar. In this way the proton has two +2/3 e plane oscillation and one linear oscillation with -1/3 e charge. The colors of quarks are coming from the three directions of coordinates and the proton is colorless. The flavors of quarks are the possible oscillations differently by energy and if they are plane or linear oscillations. We know there is no possible reflecting two oscillations to each other which are completely orthogonal, so the quarks never can be free, however there is an asymptotic freedom while their energy are increasing to turn them to the orthogonally. If they will be completely orthogonal then they lose this reflection and take new partners from the vacuum. Keeping the symmetry of the vacuum the new oscillations are keeping all the conservation laws, like charge, number of baryons and leptons. The all features of gluons are coming from this model. The mathematics of reflecting oscillators show Fermi statistics. Important to mention that in the Deuteron there are 3 quarks of +2/3 and -1/3 charge, that is three u and d quarks making the complete symmetry and because this its high stability. The Pauli Exclusion Principle says that the diffraction points are exclusive! The Weak Interaction The weak interaction transforms an electric charge in the diffraction pattern from one side to the other side, causing an electric dipole momentum change, which violates the CP and time reversal symmetry. Another important issue of the quark model is when one quark changes its flavor such that a linear oscillation transforms into plane oscillation or vice versa, changing the charge value with 1 or -1. This kind of change in the oscillation mode requires not only parity change, but also charge and time changes (CPT symmetry) resulting a right handed anti-neutrino or a left handed neutrino. The right handed anti-neutrino and the left handed neutrino exist only because changing back the quark flavor could happen only in reverse order, because they are different geometrical constructions, the u is 2 dimensional and positively charged and the d is 1 dimensional and negatively charged. It needs also a time reversal, because anti particle (anti neutrino) is involved. The neutrino is a 1/2spin creator particle to make equal the spins of the weak interaction, for example neutron decay to 2 fermions, every particle is fermions with ½ spin. The weak interaction changes the entropy since more or less particles will give more or less freedom of movement. The entropy change is a result of temperature change and breaks the equality of oscillator diffraction intensity of the Maxwell–Boltzmann statistics. This way it changes the time coordinate measure and makes possible a different time dilation as of the special relativity. The limit of the velocity of particles as the speed of light appropriate only for electrical charged particles, since the accelerated charges are self maintaining locally the accelerating electric force. The neutrinos are CP symmetry breaking particles compensated by time in the CPT symmetry, that is the time coordinate not works as in the electromagnetic interactions, consequently the speed of neutrinos is not limited by the speed of light. The weak interaction T-asymmetry is in conjunction with the T-asymmetry of the second law of thermodynamics, meaning that locally lowering entropy (on extremely high temperature) causes the weak interaction, for example the Hydrogen fusion. Probably because it is a spin creating movement changing linear oscillation to 2 dimensional oscillation by changing d to u quark and creating anti neutrino going back in time relative to the proton and electron created from the neutron, it seems that the anti neutrino fastest then the velocity of the photons created also in this weak interaction? A quark flavor changing shows that it is a reflection changes movement and the CP- and Tsymmetry breaking. This flavor changing oscillation could prove that it could be also on higher level such as atoms, molecules, probably big biological significant molecules and responsible on the aging of the life. Important to mention that the weak interaction is always contains particles and antiparticles, where the neutrinos (antineutrinos) present the opposite side. It means by Feynman’s interpretation that these particles present the backward time and probably because this they seem to move faster than the speed of light in the reference frame of the other side. Finally since the weak interaction is an electric dipole change with ½ spin creating; it is limited by the velocity of the electromagnetic wave, so the neutrino’s velocity cannot exceed the velocity of light. The General Weak Interaction The Weak Interactions T-asymmetry is in conjunction with the T-asymmetry of the Second Law of Thermodynamics, meaning that locally lowering entropy (on extremely high temperature) causes for example the Hydrogen fusion. The arrow of time by the Second Law of Thermodynamics shows the increasing entropy and decreasing information by the Weak Interaction, changing the temperature dependent diffraction patterns. A good example of this is the neutron decay, creating more particles with less known information about them. The neutrino oscillation of the Weak Interaction shows that it is a general electric dipole change and it is possible to any other temperature dependent entropy and information changing diffraction pattern of atoms, molecules and even complicated biological living structures. We can generalize the weak interaction on all of the decaying matter constructions, even on the biological too. This gives the limited lifetime for the biological constructions also by the arrow of time. There should be a new research space of the Quantum Information Science the 'general neutrino oscillation' for the greater then subatomic matter structures as an electric dipole change. There is also connection between statistical physics and evolutionary biology, since the arrow of time is working in the biological evolution also. The Fluctuation Theorem says that there is a probability that entropy will flow in a direction opposite to that dictated by the Second Law of Thermodynamics. In this case the Information is growing that is the matter formulas are emerging from the chaos. So the Weak Interaction has two directions, samples for one direction is the Neutron decay, and Hydrogen fusion is the opposite direction. Fermions and Bosons The fermions are the diffraction patterns of the bosons such a way that they are both sides of the same thing. The Higgs boson or Higgs particle is a proposed elementary particle in the Standard Model of particle physics. The Higgs boson's existence would have profound importance in particle physics because it would prove the existence of the hypothetical Higgs field - the simplest of several proposed explanations for the origin of the symmetry-breaking mechanism by which elementary particles gain mass. [3] The fermions' spin The moving charges are accelerating, since only this way can self maintain the electric field causing their acceleration. The electric charge is not point like! This constant acceleration possible if there is a rotating movement changing the direction of the velocity. This way it can accelerate forever without increasing the absolute value of the velocity in the dimension of the time and not reaching the velocity of the light. The Heisenberg uncertainty relation says that the minimum uncertainty is the value of the spin: 1/2 h = d x d p or 1/2 h = d t d E, that is the value of the basic energy status. What are the consequences of this in the weak interaction and how possible that the neutrinos' velocity greater than the speed of light? The neutrino is the one and only particle doesn’t participate in the electromagnetic interactions so we cannot expect that the velocity of the electromagnetic wave will give it any kind of limit. The neutrino is a 1/2spin creator particle to make equal the spins of the weak interaction, for example neutron decay to 2 fermions, every particle is fermions with ½ spin. The weak interaction changes the entropy since more or less particles will give more or less freedom of movement. The entropy change is a result of temperature change and breaks the equality of oscillator diffraction intensity of the Maxwell–Boltzmann statistics. This way it changes the time coordinate measure and makes possible a different time dilation as of the special relativity. The source of the Maxwell equations The electrons are accelerating also in a static electric current because of the electric force, caused by the potential difference. The magnetic field is the result of this acceleration, as you can see in [2]. The mysterious property of the matter that the electric potential difference is self maintained by the accelerating electrons in the electric current gives a clear explanation to the basic sentence of the relativity that is the velocity of the light is the maximum velocity of the matter. If the charge could move faster than the electromagnetic field than this self maintaining electromagnetic property of the electric current would be failed. Also an interesting question, how the changing magnetic field creates a negative electric field? The answer also the accelerating electrons will give. When the magnetic field is increasing in time by increasing the electric current, then the acceleration of the electrons will increase, decreasing the charge density and creating a negative electric force. Decreasing the magnetic field by decreasing the electric current will decrease the acceleration of the electrons in the electric current and increases the charge density, creating an electric force also working against the change. In this way we have explanation to all interactions between the electric and magnetic forces described in the Maxwell equations. The second mystery of the matter is the mass. We have seen that the acceleration change of the electrons in the flowing current causing a negative electrostatic force. This is the cause of the relativistic effect - built-in in the Maxwell equations - that is the mass of the electron growing with its acceleration and its velocity never can reach the velocity of light, because of this growing negative electrostatic force. The velocity of light is depending only on 2 parameters: the magnetic permeability and the electric permittivity. There is a possibility of the polarization effect created by electromagnetic forces creates the negative and positive charges. In case of equal mass as in the electron-positron pair it is simply, but on higher energies can be asymmetric as the electron-proton pair of neutron decay by week interaction and can be understood by the Feynman graphs. Anyway the mass can be electromagnetic energy exceptionally and since the inertial and gravitational mass are equals, the gravitational force is electromagnetic force and since only the magnetic force is attractive between the same charges, is very important for understanding the gravitational force. The Uncertainty Relations of Heisenberg gives the answer, since only this way can be sure that the particles are oscillating in some way by the electromagnetic field with constant energies in the atom indefinitely. Also not by chance that the uncertainty measure is equal to the fermions spin, which is one of the most important feature of the particles. There are no singularities, because the moving electron in the atom accelerating in the electric field of the proton, causing a charge distribution on delta x position difference and with a delta p momentum difference such a way that they product is about the half Planck reduced constant. For the proton this delta x much less in the nucleon, than in the orbit of the electron in the atom, the delta p is much higher because of the greatest proton mass. The Special Relativity The mysterious property of the matter that the electric potential difference is self maintained by the accelerating electrons in the electric current gives a clear explanation to the basic sentence of the relativity that is the velocity of the light is the maximum velocity of the matter. If the charge could move faster than the electromagnetic field than this self maintaining electromagnetic property of the electric current would be failed. The Heisenberg Uncertainty Principle Moving faster needs stronger acceleration reducing the dx and raising the dp. It means also mass increasing since the negative effect of the magnetic induction, also a relativistic effect! The Uncertainty Principle also explains the proton – electron mass rate since the dx is much less requiring bigger dp in the case of the proton, which is partly the result of a bigger mass mp because of the higher electromagnetic induction of the bigger frequency (impulse). The Gravitational force The changing magnetic field of the changing current causes electromagnetic mass change by the negative electric field caused by the changing acceleration of the electric charge. The gravitational attractive force is basically a magnetic force. The same electric charges can attract one another by the magnetic force if they are moving parallel in the same direction. Since the electrically neutral matter is composed of negative and positive charges they need 2 photons to mediate this attractive force, one per charges. The Bing Bang caused parallel moving of the matter gives this magnetic force, experienced as gravitational force. Since graviton is a tensor field, it has spin = 2, could be 2 photons with spin = 1 together. You can think about photons as virtual electron – positron pairs, obtaining the necessary virtual mass for gravity. The mass as seen before a result of the diffraction, for example the proton – electron mass rate Mp = 1840 Me. In order to move one of these diffraction maximum (electron or proton) we need to intervene into the diffraction pattern with a force appropriate to the intensity of this diffraction maximum, means its intensity or mass. [1] The Big Bang caused acceleration created radial currents of the matter, and since the matter is composed of negative and positive charges, these currents are creating magnetic field and attracting forces between the parallel moving electric currents. This is the gravitational force experienced by the matter, and also the mass is result of the electromagnetic forces between the charged particles. The positive and negative charged currents attracts each other or by the magnetic forces or by the much stronger electrostatic forces!? The gravitational force attracting the matter, causing concentration of the matter in a small space and leaving much space with low matter concentration: dark matter and energy. There is an asymmetry between the mass of the electric charges, for example proton and electron, can understood by the asymmetrical Planck Distribution Law. This temperature dependent energy distribution is asymmetric around the maximum intensity, where the annihilation of matter and antimatter is a high probability event. The asymmetric sides are creating different frequencies of electromagnetic radiations being in the same intensity level and compensating each other. One of these compensating ratios is the electron – proton mass ratio. The lower energy side has no compensating intensity level, it is the dark energy and the corresponding matter is the dark matter. The Graviton In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory. If it exists, the graviton is expected to be massless (because the gravitational force appears to have unlimited range) and must be a spin-2 boson. The spin follows from the fact that the source of gravitation is the stress-energy tensor, a second-rank tensor (compared to electromagnetism's spin-1 photon, the source of which is the four-current, a first-rank tensor). Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field must couple to (interact with) the stress-energy tensor in the same way that the gravitational field does. This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton, so that the only experimental verification needed for the graviton may simply be the discovery of a massless spin-2 particle. [3] What is the Spin? So we know already that the new particle has spin zero or spin two and we could tell which one if we could detect the polarizations of the photons produced. Unfortunately this is difficult and neither ATLAS nor CMS are able to measure polarizations. The only direct and sure way to confirm that the particle is indeed a scalar is to plot the angular distribution of the photons in the rest frame of the centre of mass. A spin zero particles like the Higgs carries no directional information away from the original collision so the distribution will be even in all directions. This test will be possible when a much larger number of events have been observed. In the mean time we can settle for less certain indirect indicators. The Casimir effect The Casimir effect is related to the Zero-point energy, which is fundamentally related to the Heisenberg uncertainty relation. The Heisenberg uncertainty relation says that the minimum uncertainty is the value of the spin: 1/2 h = dx dp or 1/2 h = dt dE, that is the value of the basic energy status. The moving charges are accelerating, since only this way can self maintain the electric field causing their acceleration. The electric charge is not point like! This constant acceleration possible if there is a rotating movement changing the direction of the velocity. This way it can accelerate forever without increasing the absolute value of the velocity in the dimension of the time and not reaching the velocity of the light. In the atomic scale the Heisenberg uncertainty relation gives the same result, since the moving electron in the atom accelerating in the electric field of the proton, causing a charge distribution on delta x position difference and with a delta p momentum difference such a way that they product is about the half Planck reduced constant. For the proton this delta x much less in the nucleon, than in the orbit of the electron in the atom, the delta p is much higher because of the greater proton mass. This means that the electron is not a point like particle, but has a real charge distribution. Electric charge and electromagnetic waves are two sides of the same thing; the electric charge is the diffraction center of the electromagnetic waves, quantified by the Planck constant h. The Fine structure constant The Planck constant was first described as the proportionality constant between the energy (E) of a photon and the frequency (ν) of its associated electromagnetic wave. This relation between the energy and frequency is called the Planck relation or the Planck–Einstein equation: Since the frequency , wavelength λ, and speed of light c are related by λν = c, the Planck relation can also be expressed as Since this is the source of Planck constant, the e electric charge countable from the Fine structure constant. This also related to the Heisenberg uncertainty relation, saying that the mass of the proton should be bigger than the electron mass because of the difference between their wavelengths. The expression of the fine-structure constant becomes the abbreviated This is a dimensionless constant expression, 1/137 commonly appearing in physics literature. This means that the electric charge is a result of the electromagnetic waves diffractions, consequently the proton – electron mass rate is the result of the equal intensity of the corresponding electromagnetic frequencies in the Planck distribution law, described in my diffraction theory. Conclusions There is an asymmetry between the mass of the electric charges, for example proton and electron, can understood by the asymmetrical Planck Distribution Law. This temperature dependent energy distribution is asymmetric around the maximum intensity, where the annihilation of matter and antimatter is a high probability event. We can generalize the weak interaction on all of the decaying matter constructions, even on the biological too. This gives the limited lifetime for the biological constructions also by the arrow of time. The Fluctuation Theorem says that there is a probability that entropy will flow in a direction opposite to that dictated by the Second Law of Thermodynamics. In this case the Information is growing that is the matter formulas are emerging from the chaos. So the Weak Interaction has two directions, samples for one direction is the Neutron decay, and Hydrogen fusion is the opposite direction. References [1] http://www.academia.edu/3834454/3_Dimensional_String_Theory [2] http://www.academia.edu/3833335/The_Magnetic_field_of_the_Electric_current [3] http://www.academia.edu/4158863/Higgs_Field_and_Quantum_Gravity [4] https://www.newscientist.com/article/mg22730354-600-possible-new-particle-hints-thatuniverse-maynot-be-left-handed [5] Neutrinos: Ghosts of the Universe http://discovermagazine.com/2014/sept/9ghosts-of-the-universe [6] What the universe's most elusive particles can tell us about the universe's most energetic objects http://phys.org/news/2016-04-universe-elusive-particles-energetic.html [7] Neutrinos hint at why antimatter didn’t blow up the universe https://www.newscientist.com/article/2095968-neutrinos-hint-at-why-antimatter-didnt-blow-uptheuniverse [8] Surprising neutrino decoherence inside supernovae http://phys.org/news/2016-07-neutrino- decoherence-supernovae.html [9] Weird quantum effects stretch across hundreds of miles http://phys.org/news/2016-07-weird- quantum-effects-hundreds-miles.html [10] As hunt for sterile neutrino continues, mystery deepens http://phys.org/news/2016-10-sterile- neutrino-mystery-deepens.html [11] In search of 'sterile' neutrinos http://phys.org/news/2016-12-sterile-neutrinos.html [12] World's smallest neutrino detector observes elusive interactions of particles https://phys.org/news/2017-08-world-smallest-neutrino-detector-elusive.html [13] Possible explanation for the dominance of matter over antimatter in the Universe https://www.sciencedaily.com/releases/2017/08/170804083109.htm [14] Imagining the possibility of life in a universe without the weak force https://phys.org/news/2018-02-possibility-life-universe-weak.html [15] First high-precision measurement of the mass of the W boson at the LHC https://phys.org/news/2018-02-high-precision-mass-boson-lhc.html [16] Neutrino experiments look to reveal big answers about how these fundamental particles interact with matter https://phys.org/news/2018-02-neutrino-reveal-big-fundamental-particles.html [17] First particle tracks seen in prototype for international neutrino experiment https://phys.org/news/2018-09-particle-tracks-prototype-international-neutrino.html [18] Possible explanation for excess of electron neutrinos detected by IceCube Neutrino Observatory https://phys.org/news/2018-10-explanation-excess-electron-neutrinos-icecube.html [19] Fermilab scientists lead quest to find elusive fourth kind of neutrino https://phys.org/news/2019-01-fermilab-scientists-quest-elusive-fourth.html [20] Identifying lower-energy neutrinos with a liquid-argon particle detector https://phys.org/news/2019-01-lower-energy-neutrinos-liquid-argon-particle-detector.html [21] New characterization methods developed to identify light elements https://phys.org/news/2022-10-characterization-methods-elements.html