Abstract
In this work, we present a systematic study on the feasibility of probing the largely unexplored transverse momentum dependent gluon Sivers function (GSF) in open charm production, high p$_T$ charged di-hadron and di-jet production at a future high energy, high luminosity Electron-Ion Collider (EIC). The Sivers function is a measure for the anisotropy of the parton distributions in momentum space inside a transversely polarized nucleon. It is proposed that it can be studied through single spin asymmetries in the photon-gluon fusion subprocess in electron proton collisions at the EIC. Using a well tuned Monte Carlo model for deep inelastic scattering, we estimate the possible constraints of the GSF from the future EIC data. A comparison of all the accessible measurements illustrates that the di-jet channel is the most promising way to constrain the magnitude of the GSF over a wide kinematic range.
Highlights
In recent years, an important topic in hadron physics has been the exploration of the 2 þ 1-dimensional partonic structure of nucleons by including information on the internal parton transverse momentum- and coordinate-space distributions
The transverse momentum structure of nucleons is encoded in the transverse-momentum-dependent parton distribution functions (TMDs) [1], which contain information on both the longitudinal momentum fraction x and the transverse motion k⊥ of quarks and gluons inside a fast-moving nucleon
The only direct constraint of the gluon Sivers function (GSF) comes from the left-right asymmetry AN data in p↑p → π0X within the so-called TMD generalized parton model (GPM) framework [18]
Summary
An important topic in hadron physics has been the exploration of the 2 þ 1-dimensional partonic structure of nucleons by including information on the internal parton transverse momentum- and coordinate-space distributions. The only direct constraint of the GSF comes from the left-right asymmetry AN data in p↑p → π0X within the so-called TMD generalized parton model (GPM) framework [18] This analysis found that the gluon Sivers function is not large [19]. At this moment the only experimental constraint on the gluon Sivers function in the TMD framework comes from the recent SIDIS measurement of high-pT hadron pairs off transversely polarized deuterons and protons at COMPASS [20] This analysis found that the gluon Sivers asymmetry is negative at large xB within statistical uncertainties. [22] suggested that the spin asymmetries measured in heavy quark pair and dijet production at an EIC can be used to study the Weizsäcker-Williams (WW) gluon TMDs including the Sivers function.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have