Proton-deuteron asymmetry in Drell-Yan processes and polarized light-antiquark distributions

TL;DR

This paper explores how the ratio of proton-deuteron to proton-proton Drell-Yan cross sections can reveal flavor asymmetries in polarized light-antiquark distributions, including transversity, which are otherwise difficult to measure.

Contribution

It introduces a formalism linking cross section ratios to flavor asymmetries in polarized antiquark and transversity distributions, highlighting a novel measurement approach.

Findings

Cross section ratios can identify flavor asymmetries in polarized antiquark distributions.

The method enables measurement of transversity asymmetries, inaccessible via W production or inclusive scattering.

The formalism provides a new tool for studying spin-dependent parton distributions.

Abstract

We discuss the relation between the ratio of the proton-deuteron (pd) Drell-Yan cross section to the proton-proton (pp) one \Delta_{(T)} \sigma_{pd}/2 \Delta_{(T)} \sigma_{pp} and the flavor asymmetry in polarized light-antiquark distributions. Using a recent formalism of the polarized pd Drell-Yan process, we show that the difference between the pp and pd cross sections is valuable for finding not only the flavor asymmetry in longitudinally polarized antiquark distributions but also the one in transversity distributions. It is especially important that we point out the possibility of measuring the flavor asymmetry in the transversity distributions because it cannot be found in W production processes and inclusive lepton scattering due to the chiral-odd property.