Recent Longitudinal Spin Asymmetry Measurements for Inclusive Jet Production at STAR

TL;DR

This paper reports measurements of the longitudinal spin asymmetry in inclusive jet production at STAR, providing new constraints on the polarized gluon distribution in polarized proton collisions at 200 GeV.

Contribution

It presents the first detailed $A_{LL}$ measurements for inclusive jets at STAR in the specified kinematic range, constraining gluon polarization models.

Findings

Measured $A_{LL}$ values agree with some polarized gluon distribution predictions.

Results significantly restrict the range of allowable gluon polarization within the studied x-range.

Data enhances understanding of proton spin structure.

Abstract

We present measurements of the longitudinal spin asymmetry, $A_{LL}$, for the inclusive jet signal at STAR. The data presented here are mid-rapidity jets in the transverse momentum range of $5<pT<35$ GeV/c and come from polarized proton-proton collisions at center of mass energies of $\sqrt{s}=200$ GeV. We compare our measured $A_{LL}$ values to predictions derived from various parameterizations of the polarized gluon distribution function. The results are shown to provide significant constraints for allowable gluon parameterizations within the measurement's kinematic Bjorken-x range of $0.03<x<0.3$.