Longitudinal double-spin asymmetry for inclusive jet and dijet production in polarized proton collisions at $\sqrt{s}=510$ GeV

TL;DR

This paper presents precise measurements of the double-spin asymmetry in inclusive jet and dijet production in polarized proton collisions at 510 GeV, providing new constraints on the polarized gluon distribution within the proton.

Contribution

It offers improved and more precise measurements of $A_{LL}$ at 510 GeV, especially at low dijet invariant mass, enhancing understanding of the gluon polarization in the proton.

Findings

Measurements agree with previous data and theoretical predictions.

Data constrains the shape of the polarized gluon distribution.

Results improve the precision of gluon polarization at low x.

Abstract

We report measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for inclusive jet and dijet production in polarized proton-proton collisions at midrapidity and center-of-mass energy $\sqrt{s}$ = 510 GeV, using the high luminosity data sample collected by the STAR experiment in 2013. These measurements complement and improve the precision of previous STAR measurements at the same center-of-mass energy that probe the polarized gluon distribution function at partonic momentum fraction 0.015 $\lesssim x \lesssim$ 0.25. The dijet asymmetries are separated into four jet-pair topologies, which provide further constraints on the $x$ dependence of the polarized gluon distribution function. These measurements are in agreement with previous STAR measurements and with predictions from current next-to-leading order global analyses. They provide more precise data at low dijet invariant mass that will better constraint the shape of the polarized gluon distribution function of the proton.