The Sivers Asymmetry in Hadronic Dijet Production

TL;DR

This paper develops a QCD-based formalism to predict the Sivers asymmetry in dijet production in polarized proton collisions, providing results consistent with RHIC experimental data.

Contribution

It introduces a transverse momentum dependent formalism for Sivers asymmetry in dijet production, including resummation of large logarithms and flavor separation techniques.

Findings

Predicted Sivers asymmetries match preliminary RHIC results.

Separated u- and d-quark contributions to asymmetry.

Provided a framework for future experimental analysis.

Abstract

We study the single spin asymmetry in the back-to-back dijet production in transversely polarized proton-proton collisions. Such an asymmetry is generated by the Sivers functions in the incoming polarized proton. We propose a QCD formalism in terms of the transverse momentum dependent parton distribution functions, which allow us to resum the large logarithms that arise in the perturbative calculations. We make predictions for the Sivers asymmetry of hadronic dijet production at the kinematic region that is relevant to the experiment at the Relativistic Heavy Ion Collider (RHIC). We further compute the spin asymmetries in the selected positive and negative jet charge bins, to separate the contributions from $u$- and $d$-quark Sivers functions. We find that both the sign and size of our numerical results are roughly consistent with the preliminary results from the STAR collaboration at the RHIC.