Predicting the $\sin\phi_S$ Transverse Single-spin Asymmetry of Pion Production at an Electron Ion Collider

TL;DR

This paper predicts the size of the $ ext{sin}\phi_S$ transverse single-spin asymmetry in pion production at an Electron Ion Collider, highlighting its potential measurability and the impact of QCD evolution effects.

Contribution

It provides the first prediction of the $ ext{sin}\phi_S$ asymmetry in pion production at EIC using recent parametrizations and studies the effect of QCD evolution on this asymmetry.

Findings

Asymmetry is sizable and measurable at EIC.

QCD evolution significantly impacts the asymmetry.

Predictions cover charged and neutral pion production.

Abstract

We study the transverse single-spin asymmetry with a $\sin\phi_S$ modulation in semi-inclusive deep inelastic scattering. Particularly, we consider the case in which the transverse momentum of the final state hadron is integrated out. Thus, the asymmetry is merely contributed by the coupling of the transversity distribution function $h_1(x)$ and the twist-3 collinear fragmentation function $\tilde{H}(z)$. Using the available parametrization of $h_1(x)$ from SIDIS data and the recent extracted result for $\tilde{H}(z)$, we predict the $\sin\phi_S$ asymmetry for charged and neutral pion production at an Electron Ion Collider. We find that the asymmetry is sizable and could be measured. We also study the impact of the leading-order QCD evolution effect and find that it affects the $\sin\phi_S$ asymmetry at EIC considerably.