Threshold Resummation for Polarized High-$p_T$ Hadron Production at COMPASS

TL;DR

This paper performs an all-order resummation of threshold logarithms in polarized high-$p_T$ hadron production, providing theoretical predictions for COMPASS experiment data and enhancing understanding of soft gluon effects.

Contribution

It introduces a next-to-leading logarithmic resummation technique for the direct photoproduction process in polarized collisions, improving theoretical accuracy.

Findings

Resummation improves agreement with COMPASS data.

Threshold effects are significant at high transverse momentum.

The approach enhances predictions for polarized hadron production.

Abstract

We study the cross section for the photoproduction process $\gamma N\rightarrow h X$ where the incident photon and nucleon are longitudinally polarized and a hadron $h$ is observed at high transverse momentum. Specifically, we address the "direct" part of the cross section, for which the photon interacts in a pointlike way. For this contribution we perform an all-order resummation of logarithmic threshold corrections generated by soft or collinear gluon emission to next-to-leading logarithmic accuracy. We present phenomenological results relevant for the COMPASS experiment and compare to recent COMPASS data.