Collins function and the single transverse spin asymmetry.
We study the Collins mechanism for the single transverse spin asymmetry in the collinear factorization approach. The corresponding twist-three fragmentation function is identified. We show that the Collins function calculated in this approach is universal. We further examine its contribution to the single transverse spin asymmetry of semi-inclusive hadron production in deep inelastic scattering and demonstrate that the transverse momentum dependent and twist-three collinear approaches are consistent in the intermediate transverse momentum region where both apply.
Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Feng
F
Yuan
Jian
J
Zhou