New Results and Future Experiments on Double Spin Asymmetry $A_{LT}$ in DIS Pion Electroproduction on $^{3}$He

We report the final results for the first measurement of the double-spin asymmetry $A_{LT}$ of charged pion electroproduction in deep inelastic electron scattering on a transversely polarized $^{3}$He target, obtained by reversing the electron beam helicity at 30 Hz. The corresponding neutron $A_{LT}$ asymmetries were extracted. The kinematics were focused on the valence quark region, $x\sim0.16 \mbox{-}0.35$, with $Q^{2}\sim1.4\mbox{-}2.7\,\textrm{GeV}^{2}$. These new data probe the transverse momentum dependent parton distribution function $g_{1T}^{q}$ and therefore provide direct access to quark spin-orbit correlations. This experiment has laid the foundation for future high-precision measurements using an approved large acceptance spectrometer, which will also be discussed in this talk.