Dijet Cross Section and Longitudinal Double Spin Asymmetry Measurements in Polarized Proton-proton Collisions at \sqrt{s}=200 GeV at STAR

TL;DR

This paper reports preliminary measurements of dijet cross sections and double spin asymmetries in polarized proton collisions at 200 GeV, comparing results with theoretical predictions and discussing implications for proton spin structure.

Contribution

It presents the first measurements of dijet cross sections and asymmetries at RHIC at 200 GeV, providing data to constrain polarized parton distribution functions.

Findings

Dijet cross sections agree with NLO pQCD predictions.

Double spin asymmetries are consistent with certain polarized PDF models.

Projected data from Run-9 will improve constraints on proton spin structure.

Abstract

These proceedings show the preliminary results of the dijet cross sections and the dijet longitudinal double spin asymmetries A_LL in polarized proton-proton collisions at \sqrt{s} = 200 GeV at the mid-rapidity |eta| < 0.8. The integrated luminosity of 5.39 pb^{-1} collected during RHIC Run-6 was used in the measurements. The preliminary results are presented as functions of the dijet invariant mass M_jj. The dijet cross sections are in agreement with next-to-leading-order pQCD predictions. The A_LL is compared with theoretical predictions based on various parameterizations of polarized parton distributions of the proton. Projected precision of data analyzed to date from Run-9 are shown.