Recent results on nucleon spin structure study at RHIC

Qinghua Xu

doi:10.1007/s11467-015-0480-2

Abstract

Both the PHENIX and STAR experiments at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are running polarized proton–proton collisions at $$\sqrt s $$ = 200 and 500 GeV. The main goal of the RHIC spin physics program is to gain deeper insight into the spin structure of the nucleon. We will give an overview of recent spin results from RHIC, particularly the study of gluon polarization via jet/hadron production and sea quark polarization via W boson production in longitudinally polarized proton–proton collisions.

Highlights

ALL measurements for jets and hadrons sensitive to the gluon polarization, as shown in Fig. 1 for the fractional contributions of different subprocesses to the inclusive jet production in pp collisions at 200 and 510 GeV [5]
The PHENIX experiment published its measurements on the single-spin asymmetry AL for W ± production as a function of ηe in pp collisions at 510 GeV using 2011, 2012, and 2013 data [30], which cover only the midrapidity range, and the AL results are consistent with the STAR results mentioned above in the same rapidity range
Recent measurement of the single-spin asymmetry AL for W ± production from 2011+2012 data at STAR, with a data sample about six times larger than that used for the first W measurement, have demonstrated new constraints on the antiquark helicity distributions Δuand Δd

Summary

Introduction

The recent results of W boson single-spin asymmetry from the 2012 data at STAR, which provide new constraints on light sea quark polarization, will be discussed. ALL measurements for jets and hadrons sensitive to the gluon polarization, as shown in Fig. 1 for the fractional contributions of different subprocesses to the inclusive jet production in pp collisions at 200 and 510 GeV [5].

Results

Conclusion