The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
C Aidala - One of the best experts on this subject based on the ideXlab platform.
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nuclear dependence of the transverse single spin asymmetry for forward Neutron Production in polarized p a collisions at snn 200 gev
Physical Review Letters, 2018Co-Authors: C Aidala, Yasutada Akiba, M Alfred, V Andrieux, K Aoki, N Apadula, H Asano, C Ayuso, B Azmoun, V BabintsevAbstract:During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward Neutron Production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward Neutron Production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different Neutron Production mechanisms is discussed as a possible explanation of the observed A dependence.
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inclusive cross section and single transverse spin asymmetry for very forward Neutron Production in polarized p p collisions at s 200 gev
Physical Review D, 2013Co-Authors: C Aidala, Yasutada Akiba, A Adare, S Afanasiev, N N Ajitanand, H Albataineh, J Alexander, K AokiAbstract:The energy dependence of the single-transverse-spin asymmetry, A(N), and the cross section for Neutron Production at very forward angles were measured in the PHENIX experiment at the Relativistic Heavy Ion Collider for polarized p + p collisions at root s = 200 GeV. The Neutrons were observed in forward detectors covering an angular range of up to 2.2 mrad. We report results for Neutrons with a momentum fraction of x(F) = 0.45 to 1.0. The energy dependence of the measured cross sections were consistent with x(F) scaling, compared to measurements by an experiment at the Intersecting Storage Ring, which measured Neutron Production in unpolarized p + p collisions at root s = 30.6-62.7 GeV. The cross sections for large x(F) Neutron Production for p + p collisions, as well as those in e + p collisions measured at the Hadron-Electron Ring Accelerator, are described by a pion exchange mechanism. The observed forward Neutron asymmetries were large, reaching A(N) = -0.08 +/- 0.02 for x(F) = 0.8; the measured backward asymmetries, for negative x(F), were consistent with zero. The observed asymmetry for forward Neutron Production is discussed within the pion exchange framework, with interference between the spin-flip amplitude due to the pion exchange and nonflip amplitudes from all Reggeon exchanges. Within the pion exchange description, the measured Neutron asymmetry is sensitive to the contribution of other Reggeon exchanges even for small amplitudes.
K Aoki - One of the best experts on this subject based on the ideXlab platform.
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nuclear dependence of the transverse single spin asymmetry for forward Neutron Production in polarized p a collisions at snn 200 gev
Physical Review Letters, 2018Co-Authors: C Aidala, Yasutada Akiba, M Alfred, V Andrieux, K Aoki, N Apadula, H Asano, C Ayuso, B Azmoun, V BabintsevAbstract:During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward Neutron Production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward Neutron Production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different Neutron Production mechanisms is discussed as a possible explanation of the observed A dependence.
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inclusive cross section and single transverse spin asymmetry for very forward Neutron Production in polarized p p collisions at s 200 gev
Physical Review D, 2013Co-Authors: C Aidala, Yasutada Akiba, A Adare, S Afanasiev, N N Ajitanand, H Albataineh, J Alexander, K AokiAbstract:The energy dependence of the single-transverse-spin asymmetry, A(N), and the cross section for Neutron Production at very forward angles were measured in the PHENIX experiment at the Relativistic Heavy Ion Collider for polarized p + p collisions at root s = 200 GeV. The Neutrons were observed in forward detectors covering an angular range of up to 2.2 mrad. We report results for Neutrons with a momentum fraction of x(F) = 0.45 to 1.0. The energy dependence of the measured cross sections were consistent with x(F) scaling, compared to measurements by an experiment at the Intersecting Storage Ring, which measured Neutron Production in unpolarized p + p collisions at root s = 30.6-62.7 GeV. The cross sections for large x(F) Neutron Production for p + p collisions, as well as those in e + p collisions measured at the Hadron-Electron Ring Accelerator, are described by a pion exchange mechanism. The observed forward Neutron asymmetries were large, reaching A(N) = -0.08 +/- 0.02 for x(F) = 0.8; the measured backward asymmetries, for negative x(F), were consistent with zero. The observed asymmetry for forward Neutron Production is discussed within the pion exchange framework, with interference between the spin-flip amplitude due to the pion exchange and nonflip amplitudes from all Reggeon exchanges. Within the pion exchange description, the measured Neutron asymmetry is sensitive to the contribution of other Reggeon exchanges even for small amplitudes.
Y Fukao - One of the best experts on this subject based on the ideXlab platform.
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single transverse spin asymmetry in very forward and very backward neutral particle Production for polarized proton collisions at s 200 gev
Physics Letters B, 2007Co-Authors: Y Fukao, M Togawa, A Bazilevsky, L C Bland, A Bogdanov, G Bunce, A Deshpande, H Enyo, Y GotoAbstract:Abstract In the 2001–2002 running period of the Relativistic Heavy Ion Collider (RHIC), transversely polarized protons were accelerated to 100 GeV for the first time, with collisions at s = 200 GeV . We present results from this run for single transverse-spin asymmetries for inclusive Production of neutral pions, photons and Neutrons of the energy region 20–100 GeV for forward and backward Production for angles between 0.3 mrad and 2.2 mrad with respect to the polarized proton direction. An asymmetry of A N = ( − 0.090 ± 0.006 ± 0.009 ) × ( 1.0 −0.24 +0.47 ) was observed for forward Neutron Production, where the errors are statistical and systematic, and the scale error is from the beam polarization uncertainty. The forward photon and π 0 , and backward Neutron, photon, and π 0 asymmetries were consistent with zero. The large Neutron asymmetry indicates a strong interference between a spin–flip amplitude, such as one pion exchange which dominates lower energy Neutron Production, and remaining spin–non-flip amplitudes such as reggeon exchange.
A Adare - One of the best experts on this subject based on the ideXlab platform.
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inclusive cross section and single transverse spin asymmetry for very forward Neutron Production in polarized p p collisions at s 200 gev
Physical Review D, 2013Co-Authors: C Aidala, Yasutada Akiba, A Adare, S Afanasiev, N N Ajitanand, H Albataineh, J Alexander, K AokiAbstract:The energy dependence of the single-transverse-spin asymmetry, A(N), and the cross section for Neutron Production at very forward angles were measured in the PHENIX experiment at the Relativistic Heavy Ion Collider for polarized p + p collisions at root s = 200 GeV. The Neutrons were observed in forward detectors covering an angular range of up to 2.2 mrad. We report results for Neutrons with a momentum fraction of x(F) = 0.45 to 1.0. The energy dependence of the measured cross sections were consistent with x(F) scaling, compared to measurements by an experiment at the Intersecting Storage Ring, which measured Neutron Production in unpolarized p + p collisions at root s = 30.6-62.7 GeV. The cross sections for large x(F) Neutron Production for p + p collisions, as well as those in e + p collisions measured at the Hadron-Electron Ring Accelerator, are described by a pion exchange mechanism. The observed forward Neutron asymmetries were large, reaching A(N) = -0.08 +/- 0.02 for x(F) = 0.8; the measured backward asymmetries, for negative x(F), were consistent with zero. The observed asymmetry for forward Neutron Production is discussed within the pion exchange framework, with interference between the spin-flip amplitude due to the pion exchange and nonflip amplitudes from all Reggeon exchanges. Within the pion exchange description, the measured Neutron asymmetry is sensitive to the contribution of other Reggeon exchanges even for small amplitudes.
P Mosteiro - One of the best experts on this subject based on the ideXlab platform.
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a fluka study of underground cosmogenic Neutron Production
Journal of Cosmology and Astroparticle Physics, 2014Co-Authors: A Empl, Ed Hungerford, R Jasim, P MosteiroAbstract:Neutrons produced by cosmic muon interactions are important contributors to backgrounds in underground detectors when searching for rare events. Typically such Neutrons can dominate the background, as they are particularly difficult to shield and detect. Since actual data is sparse and not well documented, simulation studies must be used to design shields and predict background rates. Thus validation of any simulation code is necessary to assure reliable results. This work compares in detail predictions of the FLUKA simulation code to existing data, and uses this code to report a simulation of cosmogenic backgrounds for typical detectors embedded in a water tank with liquid scintillator shielding.
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a fluka study of underground cosmogenic Neutron Production
arXiv: Instrumentation and Methods for Astrophysics, 2014Co-Authors: A Empl, Ed Hungerford, R Jasim, P MosteiroAbstract:Neutrons produced by cosmic muon interactions are important contributors to backgrounds in underground detectors when searching for rare events. Typically such Neutrons can dominate the background, as they are particularly difficult to shield and detect. Since actual data is sparse and not well documented, simulation studies must be used to design shields and predict background rates. Thus validation of any simulation code is necessary to assure reliable results. This work compares in detail the predictions of the FLUKA simulation code to existing data, and uses this code to report a simulation of cosmogenic backgrounds for typical detectors embedded in a water tank with liquid scintillator shielding.