Transverse Single Spin Asymmetry in J/ψ Production at {formula}= 200 GeV

摘要

222.1 Introduction and Formalism Sivers function describes the momentum distribution of unpolarised partons inside transversely polarised hadron [1]. In the past, there have been many attempts to extract quark Sivers functions from experimental data. Recently, a phenomenological study to estimate gluon Sivers function (GSF) was peformed in [2] by fitting GSF to data on asymmetry in the process p + p~(↑→π0) + X taken by PHENIX collaboration at RHIC [3].