Beam-Target Double Spin Asymmetry A_LT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He-3 Target at 1.4<Q^2<2.7 GeV^2

TL;DR

This paper presents the first measurement of the double-spin asymmetry $A_{LT}$ in charged pion production from deep inelastic scattering on a transversely polarized helium-3 target, providing new insights into quark spin-orbit correlations.

Contribution

It introduces the first experimental measurement of $A_{LT}$ asymmetries in charged pion electroproduction on a transversely polarized $^{3}$He target, probing the $g_{1T}^{q}$ distribution.

Findings

Positive $A_{LT}$ asymmetry for $$- production on neutron and helium-3.

$$ asymmetries are consistent with zero.

Data provide new constraints on quark spin-orbit correlations.

Abstract

We report the first measurement of the double-spin asymmetry $A_{LT}$ for charged pion electroproduction in semi\nobreakdash-inclusive deep\nobreakdash-inelastic electron scattering on a transversely polarized $^{3}$He target. The kinematics focused on the valence quark region, $0.16<x<0.35$ with $1.4<Q^{2}<2.7\,\textrm{GeV}^{2}$. The corresponding neutron $A_{LT}$ asymmetries were extracted from the measured $^{3}$He asymmetries and proton over $^{3}$He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function $g_{1T}^{q}$ and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for $\pi^{-}$ production on $^{3}$He and the neutron, while our $\pi^{+}$ asymmetries are consistent with zero.