Description/Abstract A dielectron signal for pair masses greater than [ital M][sub [pi]] is obser... more Description/Abstract A dielectron signal for pair masses greater than [ital M][sub [pi]] is observed in Nb+ Nb collisions at 1.05 GeV/nucleon beam kinetic energy. The invariant mass spectrum and the associated multiplicity distribution are presented. Comparisons are ...
... IN pA AND AA COLLISIONS PA SEIDL* Lawrence Berkeley Laboratory, Berkeley, CA 9720, USA DLS CO... more ... IN pA AND AA COLLISIONS PA SEIDL* Lawrence Berkeley Laboratory, Berkeley, CA 9720, USA DLS COLLABORATION S. BEEDOE1, J. BYSTRICKY'1, J. CARROLL1, P. FORCE1', J. GORDON'1, T. HALLMAN', G. IGO", P. KIRK'1, GF ... References 1) LH Xia ei al., Nucl. Phys. ...
Light and heavy ions particle therapy, mainly by means of protons and carbon ions, represents an ... more Light and heavy ions particle therapy, mainly by means of protons and carbon ions, represents an advantageous treatment modality for deep-seated and/or radioresistant tumours. An in-beam quality assurance principle is based on the detection of secondary particles induced by nuclear fragmentations between projectile and target nuclei. Three different strategies are currently under investigation: prompt γ rays imaging, proton interaction vertex imaging and in-beam positron emission tomography. Geant4 simulations have been performed first in order to assess the accuracy of some hadronic models to reproduce experimental data. Two different kinds of data have been considered: β(+)-emitting isotopes and prompt γ-ray production rates. On the one hand simulations reproduce experimental β(+) emitting isotopes production rates to an accuracy of 24%. Moreover simulated β(+) emitting nuclei production rate as a function of depth reproduce well the peak-to-plateau ratio of experimental data. On the other hand by tuning the tolerance factor of the photon evaporation model available in Geant4, we reduce significantly prompt γ-ray production rates until a very good agreement is reached with experimental data. Then we have estimated the total amount of induced annihilation photons and prompt γ rays for a simple treatment plan of ∼1 physical Gy in a homogenous equivalent soft tissue tumour (6 cm depth, 4 cm radius and 2 cm wide). The average annihilation photons emitted during a 45 s irradiation in a 4 π solid angle are ∼2 × 10(6) annihilation photon pairs and 10(8) single prompt γ whose energy ranges from a few keV to 10 MeV.
To clarify the analysis of our existing backward proton scattering data in terms of high momentum... more To clarify the analysis of our existing backward proton scattering data in terms of high momentum components in nuclei, we have measured exclusive cross sections for the backward energetic protons in coincidence with the gamma rays emitted by the target. At 200 MeV incident proton energy, the mass distribution of the residual nuclei from a 28Si target suggests a single
Summary The NA50 experiment at CERN SPS has been equipped with a quartz Cherenkov detector to me... more Summary The NA50 experiment at CERN SPS has been equipped with a quartz Cherenkov detector to measure the charge of projectile-like fragments emitted in interactions of the lead beam of 158 AGeV with a lead target. A fission peak has been observed in the light output distribution of the fragment detector. The information provided by the NA50 zero-degree calorimeter indicates that
Multiparticle Dynamics - Proceedings of the XXXI International Symposium, 2002
The J/psi production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as ... more The J/psi production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as a function of centrality, as measured with the electromagnetic or with the very forward calorimeters. After a first sharp variation at mid centrality, both patterns continue to fall down and exhibit a curvature change at high centrality values. This trend excludes any conventional
The transverse mass differential cross-sections for the ϱ + ω and Φ resonances is obtained, in th... more The transverse mass differential cross-sections for the ϱ + ω and Φ resonances is obtained, in the central rapidity region, in p-W and SU interactions at 200 GeV/nucleon. The measured ϱ + ω and Φ temperatures are ∼ 15% higher in SU as compared to p-W collisions. The ratio of cross-sections times branching ratios into the dimuon channel BΦσΦ(Bϱσϱ +
Quark Confinement and the Hadron Spectrum IV, 2002
The NA50 experiment at CERN has found evidence for deconfinement in central Pb-Pb collisions at 1... more The NA50 experiment at CERN has found evidence for deconfinement in central Pb-Pb collisions at 158 A GeV/c at the CERN SPS. The anomalous (with respect to ordinary nuclear absorption) suppression of J/psi has been observed in 1995 and 1996 data and has been confirmed with the 1998 data analysis, where a detailed study of the suppression pattern vs. centrality
Nucleus-Nucleus Collisions - Proceedings of the Conference Bologna 2000: Structure of the Nucleus at the Dawn of the Century, 2001
An anomalous charmonium suppression in central Pb-Pb collisions at 158 GeV/c per nucleon was obse... more An anomalous charmonium suppression in central Pb-Pb collisions at 158 GeV/c per nucleon was observed in the NA50 experiment at CERN. The ratio of the J/psi production cross section to the Drell-Yan cross section measured for several lighter colliding systems extending from p-p to S-U exhibits the exponential decrease due to ordinary absorption of the J/psi in nuclear matter. For
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005
... i Università di Cagliari and INFN, Cagliari, Italy. j CFIF - Instituto Superior Técnico, Lisb... more ... i Università di Cagliari and INFN, Cagliari, Italy. j CFIF - Instituto Superior Técnico, Lisbon, Portugal. k State University of New York at Stony Brook, Stony Brook, New York, USA. l RIKEN - The Insitute of Physical and Chemical Research, Wako, Saitama, Japan. ...
Description/Abstract A dielectron signal for pair masses greater than [ital M][sub [pi]] is obser... more Description/Abstract A dielectron signal for pair masses greater than [ital M][sub [pi]] is observed in Nb+ Nb collisions at 1.05 GeV/nucleon beam kinetic energy. The invariant mass spectrum and the associated multiplicity distribution are presented. Comparisons are ...
... IN pA AND AA COLLISIONS PA SEIDL* Lawrence Berkeley Laboratory, Berkeley, CA 9720, USA DLS CO... more ... IN pA AND AA COLLISIONS PA SEIDL* Lawrence Berkeley Laboratory, Berkeley, CA 9720, USA DLS COLLABORATION S. BEEDOE1, J. BYSTRICKY'1, J. CARROLL1, P. FORCE1', J. GORDON'1, T. HALLMAN', G. IGO", P. KIRK'1, GF ... References 1) LH Xia ei al., Nucl. Phys. ...
Light and heavy ions particle therapy, mainly by means of protons and carbon ions, represents an ... more Light and heavy ions particle therapy, mainly by means of protons and carbon ions, represents an advantageous treatment modality for deep-seated and/or radioresistant tumours. An in-beam quality assurance principle is based on the detection of secondary particles induced by nuclear fragmentations between projectile and target nuclei. Three different strategies are currently under investigation: prompt γ rays imaging, proton interaction vertex imaging and in-beam positron emission tomography. Geant4 simulations have been performed first in order to assess the accuracy of some hadronic models to reproduce experimental data. Two different kinds of data have been considered: β(+)-emitting isotopes and prompt γ-ray production rates. On the one hand simulations reproduce experimental β(+) emitting isotopes production rates to an accuracy of 24%. Moreover simulated β(+) emitting nuclei production rate as a function of depth reproduce well the peak-to-plateau ratio of experimental data. On the other hand by tuning the tolerance factor of the photon evaporation model available in Geant4, we reduce significantly prompt γ-ray production rates until a very good agreement is reached with experimental data. Then we have estimated the total amount of induced annihilation photons and prompt γ rays for a simple treatment plan of ∼1 physical Gy in a homogenous equivalent soft tissue tumour (6 cm depth, 4 cm radius and 2 cm wide). The average annihilation photons emitted during a 45 s irradiation in a 4 π solid angle are ∼2 × 10(6) annihilation photon pairs and 10(8) single prompt γ whose energy ranges from a few keV to 10 MeV.
To clarify the analysis of our existing backward proton scattering data in terms of high momentum... more To clarify the analysis of our existing backward proton scattering data in terms of high momentum components in nuclei, we have measured exclusive cross sections for the backward energetic protons in coincidence with the gamma rays emitted by the target. At 200 MeV incident proton energy, the mass distribution of the residual nuclei from a 28Si target suggests a single
Summary The NA50 experiment at CERN SPS has been equipped with a quartz Cherenkov detector to me... more Summary The NA50 experiment at CERN SPS has been equipped with a quartz Cherenkov detector to measure the charge of projectile-like fragments emitted in interactions of the lead beam of 158 AGeV with a lead target. A fission peak has been observed in the light output distribution of the fragment detector. The information provided by the NA50 zero-degree calorimeter indicates that
Multiparticle Dynamics - Proceedings of the XXXI International Symposium, 2002
The J/psi production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as ... more The J/psi production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as a function of centrality, as measured with the electromagnetic or with the very forward calorimeters. After a first sharp variation at mid centrality, both patterns continue to fall down and exhibit a curvature change at high centrality values. This trend excludes any conventional
The transverse mass differential cross-sections for the ϱ + ω and Φ resonances is obtained, in th... more The transverse mass differential cross-sections for the ϱ + ω and Φ resonances is obtained, in the central rapidity region, in p-W and SU interactions at 200 GeV/nucleon. The measured ϱ + ω and Φ temperatures are ∼ 15% higher in SU as compared to p-W collisions. The ratio of cross-sections times branching ratios into the dimuon channel BΦσΦ(Bϱσϱ +
Quark Confinement and the Hadron Spectrum IV, 2002
The NA50 experiment at CERN has found evidence for deconfinement in central Pb-Pb collisions at 1... more The NA50 experiment at CERN has found evidence for deconfinement in central Pb-Pb collisions at 158 A GeV/c at the CERN SPS. The anomalous (with respect to ordinary nuclear absorption) suppression of J/psi has been observed in 1995 and 1996 data and has been confirmed with the 1998 data analysis, where a detailed study of the suppression pattern vs. centrality
Nucleus-Nucleus Collisions - Proceedings of the Conference Bologna 2000: Structure of the Nucleus at the Dawn of the Century, 2001
An anomalous charmonium suppression in central Pb-Pb collisions at 158 GeV/c per nucleon was obse... more An anomalous charmonium suppression in central Pb-Pb collisions at 158 GeV/c per nucleon was observed in the NA50 experiment at CERN. The ratio of the J/psi production cross section to the Drell-Yan cross section measured for several lighter colliding systems extending from p-p to S-U exhibits the exponential decrease due to ordinary absorption of the J/psi in nuclear matter. For
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005
... i Università di Cagliari and INFN, Cagliari, Italy. j CFIF - Instituto Superior Técnico, Lisb... more ... i Università di Cagliari and INFN, Cagliari, Italy. j CFIF - Instituto Superior Técnico, Lisbon, Portugal. k State University of New York at Stony Brook, Stony Brook, New York, USA. l RIKEN - The Insitute of Physical and Chemical Research, Wako, Saitama, Japan. ...
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