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Title: Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized $p+A$ collisions at $$\sqrt{s_{_{NN}}}=200$$ GeV

Abstract

We report that 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 three larger in absolute value and of opposite sign. Lastly, the interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Contributing Org.:
PHENIX Collaboration
OSTI Identifier:
1416077
Alternate Identifier(s):
OSTI ID: 1413950
Report Number(s):
BNL-114783-2017-JA
Journal ID: ISSN 0031-9007; PRLTAO
Grant/Contract Number:  
SC0012704
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 120; Journal Issue: 2; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Aidala, C., Azmoun, B., Akiba, Y., Alfred, M., Andrieux, V., Aoki, K., Apadula, N., Asano, H., and et al.. Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized $p+A$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV. United States: N. p., 2018. Web. doi:10.1103/PhysRevLett.120.022001.
Aidala, C., Azmoun, B., Akiba, Y., Alfred, M., Andrieux, V., Aoki, K., Apadula, N., Asano, H., & et al.. Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized $p+A$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV. United States. doi:10.1103/PhysRevLett.120.022001.
Aidala, C., Azmoun, B., Akiba, Y., Alfred, M., Andrieux, V., Aoki, K., Apadula, N., Asano, H., and et al.. Mon . "Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized $p+A$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV". United States. doi:10.1103/PhysRevLett.120.022001.
@article{osti_1416077,
title = {Nuclear dependence of the transverse-single-spin asymmetry for forward neutron production in polarized $p+A$ collisions at $\sqrt{s_{_{NN}}}=200$ GeV},
author = {Aidala, C. and Azmoun, B. and Akiba, Y. and Alfred, M. and Andrieux, V. and Aoki, K. and Apadula, N. and Asano, H. and et al.},
abstractNote = {We report that 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 three larger in absolute value and of opposite sign. Lastly, the interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.},
doi = {10.1103/PhysRevLett.120.022001},
journal = {Physical Review Letters},
number = 2,
volume = 120,
place = {United States},
year = {Mon Jan 08 00:00:00 EST 2018},
month = {Mon Jan 08 00:00:00 EST 2018}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevLett.120.022001

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Cited by: 1 work
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