An experiment to measure single-spin asymmetries of semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized He3 target was performed at Jefferson Laboratory in the kinematic region of 0.16<x<0.35 and 1.4<Q2<2.7 GeV2. Pretzelosity asymmetries on He3, which are expressed as the convolution of the h1TâŠ¥ transverse-momentum-dependent distribution functions and the Collins fragmentation functions in the leading order, were measured for the first time. Under the effective polarization approximation, we extracted the corresponding neutron asymmetries from the measured He3 asymmetries and cross-section ratios between the proton and He3. Our results show that both π± on He3 and on neutron pretzelosity asymmetries are consistent with zero within experimental uncertainties.
ASJC Scopus subject areas
- Nuclear and High Energy Physics