Speaker
Description
The transverse single-spin asymmetry ($A_{\mathrm{N}}$) serves as a crucial probe for understanding the mechanisms of particle production in polarized high energy particle collisions as well as the internal dynamics of quarks and gluons within a polarized nucleon. The RHICf collaboration measured a non-zero transverse single-spin asymmetry ($A_{\mathrm{N}}$) for very forward ($\eta > 6$) neutral pions ($\pi^{0}$) in transversely polarized $p+p$ collisions at $\sqrt{s} = 510$ GeV within the STAR experiment. This measurement, along with a similar analysis performed at STAR for forward $\pi^{0}$s, $2.7 < \eta < 4.0$, suggests that diffractive interactions could be primarily responsible for the observed $A_{\mathrm{N}}$. To quantitatively determine the extent to which diffractive and non-diffractive processes contribute to the RHICf $A_{\mathrm{N}}$, we conduct a joint analysis of the very forward $\pi^{0}$ $A_{\mathrm{N}}$ using both RHICf and STAR detector systems from the same collisions. We report preliminary results of $\pi^{0}$ $A_{\mathrm{N}}$ in diffractive-like and non-diffractive-like event categories, and discuss the current status of this ongoing analysis.
