Transverse single-spin asymmetries in proton-proton collisions at the AFTER@LHC experiment in a TMD factorisation scheme

TL;DR

This paper predicts transverse single-spin asymmetries in proton-proton collisions at the AFTER@LHC experiment using TMD factorisation, comparing results with collinear twist-3 approaches to enhance understanding of spin effects in high-energy processes.

Contribution

It provides the first detailed predictions for $A_N$ in various processes at AFTER@LHC using TMD factorisation, and compares these with collinear twist-3 results to evaluate different theoretical frameworks.

Findings

Predicted sizable single-spin asymmetries for various processes.

Good agreement and notable differences between TMD and twist-3 approaches.

Guidance for future experimental measurements at AFTER@LHC.

Abstract

The inclusive large-$p_T$ production of a single pion, jet or direct photon, and Drell-Yan processes, are considered for proton-proton collisions in the kinematical range expected for the fixed-target experiment AFTER, proposed at LHC. For all these processes, predictions are given for the transverse single-spin asymmetry, $A_N$, computed according to a Generalised Parton Model previously discussed in the literature and based on TMD factorisation. Comparisons with the results of a collinear twist-3 approach, recently presented, are made and discussed.