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
We report the first measurement of the double-spin asymmetry ALT for
charged pion electroproduction in semi\nobreakdash-inclusive
deep\nobreakdash-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<2.7GeV2. 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.Comment: 6 pages, 2 figures, 1 tables, published in PR