Campus Units

Physics and Astronomy

Document Type

Article

Publication Version

Published Version

Publication Date

1-2018

Journal or Book Title

Physical Review Letters

Volume

120

Issue

2

First Page

022001

DOI

10.1103/PhysRevLett.120.022001

Abstract

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.

Comments

This article is published as Aidala, C., Y. Akiba, M. Alfred, V. Andrieux, K. Aoki, N. Apadula, H. Asano et al. "Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+ A Collisions at s N N= 200 GeV." Physical Review Letters 120, no. 2 (2018): 022001. DOI: 10.1103/PhysRevLett.120.022001. Posted with permission.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

Included in

Nuclear Commons

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