A_{LT} in the Nucleon-Nucleon Polarized Drell-Yan Process

TL;DR

This paper provides a leading order estimate of the longitudinal-transverse spin asymmetry in polarized nucleon-nucleon Drell-Yan processes, highlighting its small magnitude and the negligible role of twist-3 contributions.

Contribution

It offers the first LO estimate of A_{LT} in polarized Drell-Yan processes, incorporating twist-3 distributions from the bag model and comparing with other spin asymmetries.

Findings

A_{LT} is much smaller than A_{TT}.

Twist-3 contributions are negligible.

A_{LT} is significantly suppressed at high energies.

Abstract

We present a leading order (LO) estimate for the longitidinal-transverse spin asymmetry (A_{LT}) in the nucleon-nucleon polarized Drell-Yan process at RHIC and HERA-$\vec{N}$ energies in comparison with A_{LL} and A_{TT}. A_{LT} receives contribution from g_1, the transversity ditribution h_1, and the twist-3 distributions g_T and h_L. For the twist-3 contribution we use the bag model prediction evolved to a high energy scale by the large-N_c evolution equation. We found that A_{LT} (normalized by the asymmetry in the parton level) is much smaller than the corresponding A_{TT}. Twist-3 contribution given by the bag model also turned out to be negligible.