# Transverse single spin asymmetry for very forward $\pi^{0}$ production in polarized proton-proton collisions at $\sqrt{s}$ = 510 GeV

## TL;DR

This paper reports the first measurement of the transverse single spin asymmetry for very forward $<<4$ and $6<$ $$ in polarized proton-proton collisions at 510 GeV, providing new insights into the production mechanisms of $^{0}$ mesons.

## Contribution

It presents the first measurement of $A_N$ for very forward $^{0}$ production at $$ = 510 GeV in the pseudorapidity range of 6 to 8, exploring contributions beyond partonic interactions.

## Key findings

- Preliminary $A_N$ results for $6<<8$ are reported.
- Data suggests potential contributions from diffractive interactions.
- Measurement covers $0<p_T<1$ GeV/c range.

## Abstract

Transverse single spin asymmetry, $A_{N}$, of very forward $\pi^{0}$ production from polarized $p + p$ collisions provides new information toward an understanding of its production mechanism. $A_{N}$ of forward $\pi^{0}$ in the pseudorapidity region of $3 < \eta < 4$ has been described by the partonic structure of the proton in the perturbative QCD framework. However, recent data indicates a potential contribution from not only partonic but also diffractive interactions. In order to provide a new insight on the origin of the $A_{N}$, we measured the very forward $\pi^{0}$ production in the pseudorapidity region of $6 < \eta$ from $\sqrt{s}$ = 510 GeV polarized $p + p$ collisions at RHIC in 2017. We report our measurement of the very forward $\pi^{0}$ over the transverse momentum range of $0 < p_{T} < 1$ GeV/$c$ and the preliminary result.