The Experts below are selected from a list of 195738 Experts worldwide ranked by ideXlab platform
A. David - One of the best experts on this subject based on the ideXlab platform.
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NA60 results on the $\rho$ Spectral Function in In-In collisions
2006Co-Authors: S. Damjanovic, R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, A. DavidAbstract:The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. After subtraction of the decay sources, the shape of the resulting mass spectrum is largely consistent with a dominant contribution from pi+pi- -> rho -> mu+mu- annihilation. The associated rho Spectral Function exhibits considerable broadening, but essentially no shift in mass. The acceptance-corrected pT spectra have a shape atypical for radial flow. They also significantly depend on mass, pointing to different sources in different mass regions. Both mass and pT spectra are compared to recent theoretical predictions.
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First measurement of the $\rho$ Spectral Function in nuclear collisions
European Physical Journal C: Particles and Fields, 2006Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size close to 400K events and the good mass resolution of about 2% made it possible to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum shows some non-trivial centrality dependence, but is largely consistent with a dominant contribution from pi+pi- ->rho ->mu+mu- annihilation. The associated rho Spectral Function exhibits considerable broadening, but essentially no shift in mass. The pT-differential mass spectra show the excess to be much stronger at low pT than at high pT. The results are compared to theoretical model predictions; they tend to rule out models linking hadron masses directly to the chiral condensate.
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first measurement of the rho Spectral Function in high energy nuclear collisions
Physical Review Letters, 2006Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360 000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+pi--->rho-->µ+µ- annihilation. The associated space-time averaged rho Spectral Function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masses directly to the chiral condensate.
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First measurement of the rho Spectral Function in nuclear collisions
Nuclear Physics A, 2005Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:The NA60 experiment has studied low-mass muon pairs in 158 AGeV Indium-Indium collisions at the CERN SPS. A strong excess of pairs is observed above the expectation from neutral meson decays. The unprecedented sample size of 360 000 events and the good mass resolution of about 2% allow to isolate the excess by subtraction of the known sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+ pi- -> rho -> mu+ mu- annihilation. The associated rho Spectral Function shows a strong broadening, but essentially no shift in mass.
B. Coopersmith - One of the best experts on this subject based on the ideXlab platform.
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effective Spectral Function for quasielastic scattering on nuclei
Nuclear and Particle Physics Proceedings, 2016Co-Authors: Arie Bodek, M. E. Christy, B. CoopersmithAbstract:Abstract Spectral Functions do not fully describe quasielastic electron and neutrino scattering from nuclei because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the ψ ′ super-scaling formalism can be well described with a modified effective Spectral Function (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data. Our values for the binding energy parameter Δ are smaller than ϵ ¯ extracted within the Fermi gas model from pre 1971 data by Moniz [8], probably because these early cross sections were not corrected for coulomb effects.
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Effective Spectral Function for Quasielastic Scattering on Nuclei
The European Physical Journal C, 2014Co-Authors: Arie Bodek, M. E. Christy, B. CoopersmithAbstract:Spectral Functions that are used in neutrino event, generators to model quasielastic (QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritchie Fermi gas with high momentum tail, and the Benhar-Fantoni two dimensional Spectral Function. We find that the \(\nu \) dependence of predictions of these Spectral Functions for the QE differential cross sections (\({d^2\sigma }/{dQ^2 d\nu }\)) are in disagreement with the prediction of the \(\psi '\) superscaling Function which is extracted from fits to quasielastic electron scattering data on nuclear targets. It is known that Spectral Functions do not fully describe quasielastic scattering because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the \(\psi '\) superscaling formalism can be well described with a modified effective Spectral Function (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data.
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Effective Spectral Function for Quasielastic Scattering on Nuclei
viXra, 2014Co-Authors: Arie Bodek, M. E. Christy, B. CoopersmithAbstract:Spectral Functions that are used in neutrino event generators (such as GENIE, NEUT, NUANCE, NUWRO, and GiBUU) to model quasielastic(QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritche Fermi gas with high momentum tail, and the Benhar Fantoni two dimensional Spectral Function. We find that the predictions of these Spectral Functions for the d-sigma/d-nu distribution of QE events are in disagreement with the prediction of the psi' superscaling Function which is extracted from fits to quasielastic electron scattering data on nuclear targets. It is known that Spectral Functions do not fully describe quasielastic scattering because they only model the initial state. Final state interactions distort the shape of d-sigma/d-nu, reduce the cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the psi' superscaling formalism can be well described with a modified effective Spectral Function (EFS).
R. Arnaldi - One of the best experts on this subject based on the ideXlab platform.
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NA60 results on the $\rho$ Spectral Function in In-In collisions
2006Co-Authors: S. Damjanovic, R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, A. DavidAbstract:The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. After subtraction of the decay sources, the shape of the resulting mass spectrum is largely consistent with a dominant contribution from pi+pi- -> rho -> mu+mu- annihilation. The associated rho Spectral Function exhibits considerable broadening, but essentially no shift in mass. The acceptance-corrected pT spectra have a shape atypical for radial flow. They also significantly depend on mass, pointing to different sources in different mass regions. Both mass and pT spectra are compared to recent theoretical predictions.
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First measurement of the $\rho$ Spectral Function in nuclear collisions
European Physical Journal C: Particles and Fields, 2006Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size close to 400K events and the good mass resolution of about 2% made it possible to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum shows some non-trivial centrality dependence, but is largely consistent with a dominant contribution from pi+pi- ->rho ->mu+mu- annihilation. The associated rho Spectral Function exhibits considerable broadening, but essentially no shift in mass. The pT-differential mass spectra show the excess to be much stronger at low pT than at high pT. The results are compared to theoretical model predictions; they tend to rule out models linking hadron masses directly to the chiral condensate.
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first measurement of the rho Spectral Function in high energy nuclear collisions
Physical Review Letters, 2006Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360 000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+pi--->rho-->µ+µ- annihilation. The associated space-time averaged rho Spectral Function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masses directly to the chiral condensate.
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First measurement of the rho Spectral Function in nuclear collisions
Nuclear Physics A, 2005Co-Authors: R. Arnaldi, R. Averbeck, K. Banicz, J. Castor, B. Chaurand, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. DavidAbstract:The NA60 experiment has studied low-mass muon pairs in 158 AGeV Indium-Indium collisions at the CERN SPS. A strong excess of pairs is observed above the expectation from neutral meson decays. The unprecedented sample size of 360 000 events and the good mass resolution of about 2% allow to isolate the excess by subtraction of the known sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+ pi- -> rho -> mu+ mu- annihilation. The associated rho Spectral Function shows a strong broadening, but essentially no shift in mass.
L. Karlsson - One of the best experts on this subject based on the ideXlab platform.
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Profile of resonant photoelectron spectra versus the Spectral Function width and photon frequency detuning
Physical Review A, 2004Co-Authors: Raimund Feifel, F. Gel'mukhanov, M. N. Piancastelli, Cristina Miron, Vikctor Kimberg, S. Sörensen, Gunnar Öhrwall, Alexander Baev, Hans Ågren, L. KarlssonAbstract:The outermost, singly ionized valence state of N-2, the X (2)Sigma(g)(+) state, is investigated in detail as a Function of the photon frequency bandwidth for core excitation to the N 1s-->pi(*) resonance, where the photon frequency is tuned in between the first two vibrational levels of this bound intermediate electronic state. We find a strong, nontrivial dependence of the resulting resonant photoemission Spectral profile on the monochromator Function width and the frequency of its peak position. For narrow bandwidth excitation we observe a well resolved vibrational fine structure in the final electron spectrum, which for somewhat broader bandwidths gets smeared out into a continuous structure. For even broader monochromator bandwidths, it converts again into a well resolved vibrational progression. In addition, Spectral features appearing below the adiabatic transition energy of the ground state of N-2(+) are observed for broadband excitation. A model taking into account the interplay of the partial scattering cross section with the Spectral Function is presented and applied to the X (2)Sigma(g)(+) final state of N-2(+).
D A Thompson - One of the best experts on this subject based on the ideXlab platform.
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Spectral Function and responsivity of resonant tunneling and superlattice quantum dot infrared photodetectors using green s Function
Journal of Applied Physics, 2007Co-Authors: Mohamed A Naser, M J Deen, D A ThompsonAbstract:Theoretical modeling of resonant tunneling (RT) and superlattice (SL) quantum dot infrared photodetectors (QDIPs) using Green’s Function is reported. The RT QDIP gives very low dark current which improves the detectivity of the device and allows for high temperature operation. The SL QDIP gives high responsivity and is suitable for low-level signal detection. The theoretical model is based on Green’s Function method which is used to calculate the Spectral Function and the density of states of the two detectors. The kinetic equation that governs Green’s Functions is solved numerically using the method of finite differences. From the information obtained from the density of states, the possible energy transitions are obtained. The bound states are calculated by solving the eigenvalue problem using the method of finite differences, while the continuum states localized in the quantum dot region are calculated using Green’s Functions. Using the first order dipole approximation and Fermi golden rule, the eigens...
