Spin-Flavor Decomposition in Polarized Semi-Inclusive Deep Inelastic Scattering Experiments at Jefferson Lab

TL;DR

This paper discusses a Jefferson Lab experiment aimed at measuring spin asymmetries in polarized deep-inelastic scattering to better understand quark flavor contributions and polarization distributions.

Contribution

It introduces a novel experimental approach to precisely measure flavor non-singlet spin asymmetries and constrain quark and gluon polarizations in nucleons.

Findings

High-precision measurements of $A_{1n}^{ ext{pi+ - pi-}}$

Constraints on $ riangle d_v(x)$ independent of fragmentation functions

Global NLO QCD fit results on quark and gluon polarizations

Abstract

A Jefferson Lab experiment proposal was discussed in this talk. The experiment is designed to measure the beam-target double-spin asymmetries $A_{1n}^h$ in semi-inclusive deep-inelastic $\vec n({\vec e}, e^\prime \pi^+)X$ and $\vec n({\vec e}, e^\prime \pi^-)X$ reactions on a longitudinally polarized $^3$He target. In addition to $A_{1n}^h$, the flavor non-singlet combination $A_{1n}^{\pi^+ - \pi^-}$, in which the gluons do not contribute, will be determined with high precision to extract $\Delta d_v(x)$ independent of the knowledge of the fragmentation functions. The data will also impose strong constraints on quark and gluon polarizations through a global NLO QCD fit.