Beam-Target Double-Spin Asymmetry ALT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized 3He Target at 1:4<Q2 < 2:7 GeV2

Abstract

We report the first measurement of the double-spin asymmetry ALT for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized 3He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q2<2.7 GeV2. The corresponding neutron ALT asymmetries were extracted from the measured 3He asymmetries and proton over 3He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g1Tq and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π- production on 3He and the neutron, while our π+ asymmetries are consistent with zero.