Inclusive Jet $A_{LL}$ Measurements at STAR

TL;DR

This paper presents preliminary measurements of the inclusive jet longitudinal spin asymmetry $A_{LL}$ at STAR using 200 GeV polarized proton-proton collisions, providing insights into the nucleon's spin structure and constraining theoretical models.

Contribution

First measurement of inclusive jet $A_{LL}$ at STAR with 2006 data, comparing results with GRSV models to constrain polarized parton distribution functions.

Findings

Data are consistent with certain GRSV models.

Constraints on polarized gluon distribution in the nucleon.

Improved understanding of nucleon spin structure.

Abstract

We report STAR's preliminary measurement of the inclusive jet longitudinal spin asymmetry $A_{LL}$ using data from the RHIC 2006 run. The 2006 data set was taken with 200 GeV polarized proton-proton collisions and represents 4.7 $pb^{-1}$ of data. Typical beam polarizations were $\sim 55-60%$. The data are compared with theoretical calculations of $A_{LL}$ based on various GRSV models of the polarized parton distribution functions in the nucleon. Previous STAR inclusive jet $A_{LL}$ and cross section measurements are also presented, as is a discussion of constraints these data place on the allowed theoretical models.