Summary Shear wave splitting measurements in the Isthmus of Tehuantepec (IT), southern Mexico, inferred from teleseismic core phases are presented. Measurements were made along a south-to-north profile across the IT. The results show a... more
Summary Shear wave splitting measurements in the Isthmus of Tehuantepec (IT), southern Mexico, inferred from teleseismic core phases are presented. Measurements were made along a south-to-north profile across the IT. The results show a predominantly trench-normal pattern of fast polarization orientations with averaged delay times up to 2.2 s. Fast orientations near the trench suggest a corner flow in the mantle wedge and an entrained flow in the subslab region. Away the trench, fast orientations are parallel to the Absolute plate Motion, suggesting that the anisotropy in that region is driven by a simple asthenospheric flow. A comparison with splitting measurements made in the Mexican subduction zone shows a 17º clockwise rotation of the fast orientations of between east and west Mexico. This is consistent with the observed change in orientation of 19º clockwise in the Middle America Trench (MAT). This suggests that the rotation of the fast orientations is controlled by the change o...
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The High Altitude Water Cherenkov (HAWC) observatory is an array of large water Cherenkov detectors sensitive to gamma rays and hadronic cosmic rays in the energy band between 100 GeV and 100 TeV. The observatory will be used to measure... more
The High Altitude Water Cherenkov (HAWC) observatory is an array of large water Cherenkov detectors sensitive to gamma rays and hadronic cosmic rays in the energy band between 100 GeV and 100 TeV. The observatory will be used to measure high-energy protons and cosmic rays via detection of the energetic secondary particles reaching the ground when one of these particles interacts in the atmosphere above the detector. HAWC is under construction at a site 4100 meters above sea level on the northern slope of the volcano Sierra Negra, which is located in central Mexico at 19 N latitude. It is scheduled for completion in 2014. In this paper we estimate the sensitivity of the HAWC instrument to point-like and extended sources of gamma rays. The source fluxes are modeled using both unbroken power laws and power laws with exponential cutoffs. HAWC, in one year, is sensitive to point sources with integral power-law spectra as low as 5 10-13 cm-2sec-1 above 2 TeV (approximately 50 mCrab) over ...
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In this paper, we study the quasinormal modes for scalar, electromagnetic, and gravitational axial perturbations in the Hayward regular black hole surrounded by quintessence (HBH-[Formula: see text]). Using the third-order WKB... more
In this paper, we study the quasinormal modes for scalar, electromagnetic, and gravitational axial perturbations in the Hayward regular black hole surrounded by quintessence (HBH-[Formula: see text]). Using the third-order WKB approximation, we can determine the dependence of the quasinormal modes on the parameters of the regular black hole and the parameters on the test fields. We also determine the greybody factor, giving transmission and reflection coefficients of the scattered wave through the effective potentials in the WKB approximation using numerical analysis.
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List of proceedings from the HAWC Collaboration presented at the 35th International Cosmic Ray Conference, 12 July - 20 July 2017, Bexco, Busan, Korea.
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We show a simulation for the free propagation of a Gaussian and multi-spatial soliton beam in a self-refractive waveguide through the Beam Propagation Method (BPM). We observed and conjectured that a Gaussian beam can be decomposed into... more
We show a simulation for the free propagation of a Gaussian and multi-spatial soliton beam in a self-refractive waveguide through the Beam Propagation Method (BPM). We observed and conjectured that a Gaussian beam can be decomposed into Solitons by the propagation in a self-refractive media. We observe too that given the presence of nonlinearity these spatial solitons displays also self-bending phenomena.
Dispersion studies were made using the radial Klein–Gordon equation. The radial Klein–Gordon equation was solved numerically using the Yukawa potential and the solutions obtained were introduced in the [Formula: see text] matrix to... more
Dispersion studies were made using the radial Klein–Gordon equation. The radial Klein–Gordon equation was solved numerically using the Yukawa potential and the solutions obtained were introduced in the [Formula: see text] matrix to calculate the cross-sections. This analysis was made for pions with protons at high energies. The coupling constant was adjusted in the potential to compare with experimental data and to set bounds for the parameter of the model.
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The Born approximation to the quark-gluon-exchange mechanism for K + N scattering is used as a starting point to generate a potential for this system. The valence quark wave function of the nucleon is generalized from a single Gaussian to... more
The Born approximation to the quark-gluon-exchange mechanism for K + N scattering is used as a starting point to generate a potential for this system. The valence quark wave function of the nucleon is generalized from a single Gaussian to a sum of Gaussians in order to have a more flexible representation than previous work. We obtain a potential derived from a valence density given by lattice calculations. By comparing with a recent amplitude analysis it is found that the strength of the quark-gluon based potential needs to be increased by a factor of order 2-4 relative to the normalization given by more traditional values of the governing parameters. The method is used to estimate the change in effective K + N amplitudes which would result from changes in the valence quark distributions or strength of the interaction which might arise from nuclear medium effects in K + scattering from nuclei.
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Research Interests: Physics, Astronomy, Air, Annihilation, Galaxy, and 6 moreMonitoring, Observatory, New Physics, Sky, Gamma Ray, and Accelerator
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Research Interests: Physics, Active Galactic Nuclei, Gamma Ray Bursts, Astroparticle physics, Astrophysics, and 15 moreNeutrino, Astronomy, Physical sciences, Gamma Ray Burst, Observatory, Luminosity function, Science Technology, Sky, Emission, Supernova, Uncategorized, Neutrino Astronomy, Neutrinos, All Sky Survey, and Alert system
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SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star). Two jets of ionized matter with a bulk velocity of approximately... more
SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star). Two jets of ionized matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets. SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington, and the luminosity of the system is about 10 ergs per second. The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed. At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ...
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The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude... more
The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.
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The elastic differential cross section is calculated at low energies for the elements3He,20Ne,40Ar,14N,12C, and for208Pb using an effective 4D electromagnetic potential coming from the contribution of the massive Kaluza–Klein modes of the... more
The elastic differential cross section is calculated at low energies for the elements3He,20Ne,40Ar,14N,12C, and for208Pb using an effective 4D electromagnetic potential coming from the contribution of the massive Kaluza–Klein modes of the 5D vector field in a thick brane scenario. The length scale is adjusted in the potential to compare with known experimental data and to set bounds for the parameter of the model.
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Research Interests: Physics, Organic Chemistry, Physical Chemistry, Astrophysical Plasma, Dust (Astronomy & Astrophysics), and 12 moreAstrophysics, Fermi Gamma-ray Space Telescope, Nuclear, Molecular, Gamma Ray Burst, Observatory, Atomic, Gamma Ray, Cherenkov Radiation, Zenith, Redshift, and Extragalactic Background Light
Research Interests: Physics and Observatory
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Abstract: ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner... more
Abstract: ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor ...
