Speaker
Description
The Transverse Single-Spin Asymmetry ($A_{\mathrm{N}}$) provides valuable insights into the motion and structure of quarks and gluons within a nucleon. The RHICf experiment, in collaboration with the STAR experiment, measured neutral particles in very forward ($\eta > 6$) regions in transversely polarized $p+p$ collisions at $\sqrt{s}$ = 510 GeV during the 2017 data-taking period. Previous results from the RHICf Collaboration indicated that the $A_{\mathrm{N}}$ of inclusive neutral pions is non-zero within $\eta > 6$ and $p_{\mathrm{T}, \pi^{0}} < 1$ GeV/$c$. The result also hinted a potentially large contribution from soft processes, such as diffractive reactions. On the other hand, it raises a new question of whether contributions from non-diffractive processes are completely excluded. In this study, we present and compare the $A_{\mathrm{N}}$ for neutral pions in Diffractive-Like and Non-Diffractive-Like events. Event classification is performed based on the particle distribution measured by the STAR detector system. The results highlight the trends in $A_{\mathrm{N}}$ for neutral pions between diffractive and non-diffractive processes.
