Measuring The Gluon Sivers Function At A Future Electron-ion Collider

Abstract

Sivers function describes the anisotropy of parton distributions inside a transversely polarized nucleon in the momentum space. The study of the largely unexplored gluon Sivers function (GSF) is important to obtain a complete picture of the 2+1D momentum structure of nucleons. It is proposed that the GSF can be studied through dihadron single spin asymmetry (SSA) with collisions of electrons on transversely polarized protons at a future high energy, high luminosity Electron-Ion Collider (EIC). In this work, a detailed study on the feasibility of measuring the dihadron SSA arising from the GSF is presented. Due to significantly larger statistics, we find final states with charged dihadron pairs are more sensitive to GSF as compared to $K^{+}K^{-}$ and $D\bar{D}$ final states.