Speaker
Description
I will talk about our recent computation [1] of a gT(x) contribution to transverse single spin asymmetry (SSA) in SIDIS in a collinear framework. In [1] we have found that gT(x) first appears at two-loops. I will explain main steps of our calculation and show the final formula for the cross section [2] in the Wilczek-Wandzura (WW) approximation, that is, neglecting the genuine twist-3 pieces. In the WW approximation gT(x) is given as an integral of the helicity distribution, which is known from global fits. In this way, an explicit evaluation of SSA has no free parameters in principle. I will show our results from an extensive numerical computation for the spin dependent moments A_UT, such as Sivers and Collins moment, coming from gT [2], for the future EIC kinematics. Finally, I will make comments about an analogue contribution in the gluon initiated channel arising from the G_3T(x) that is also included in our full numerical setup.
[1] S. B., Y. Hatta, H-n. Li, D.-J. Yang, Phys. Rev. D 100 (2019) 9, 094027
[2] S. B., Y. Hatta, A. Kaushik, H.-n. Li, in preparation
