2023/07/15 by M. H. Kim, Kim, M. H.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Particle Detector Development and Performance #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2307.07673
openalex publication_date 2023/07/15 · openalex created_date 2023/07/19 · openalex updated_date 2026/07/28
In the high-energy p+p collisions, the transverse single spin asymmetry for very forward neutron production has been interpreted by an interference between π (spin flip) and a1 (spin non-flip) exchange with a non-zero phase shift. The π and a1 exchange model predicted the neutron asymmetry would increase in magnitude with transverse momentum (p_\scriptsize\textrmT) in p_\scriptsize\textrmT < 0.4 GeV/c. In June 2017, the RHICf experiment installed an electromagnetic calorimeter at the zero-degree area of the STAR experiment at the Relativistic Heavy Ion Collider and measured the neutron asymmetry in a wide p_\scriptsize\textrmT range of 0 < p_\scriptsize\textrmT < 1 GeV/c from polarized p+p collisions at √(s) = 510 GeV. The RHICf data allows us to investigate the kinematic dependence of the neutron asymmetry in detail, which not only can test the π and a1 exchange model in the higher p_\scriptsize\textrmT range but also can study the √(s) dependence by comparing with the previous measurements. We present the preliminary result and analysis status of the neutron asymmetry measured by the RHICf experiment. In order to understand the RHICf result, a theoretical calculation other than Reggeon exchange will also be discussed.