Speaker
Description
One of the primary goals of the RHIC spin program is to determine the polarized gluon distribution
function, $\Delta g$, within the proton. At the leading order, proton-proton collisions involve a mixture of
quark-quark, quark-gluon, and gluon-gluon scatterings. At RHIC kinematics, the quark-gluon
and gluon-gluon contributions dominate, which makes RHIC an ideal tool to study $\Delta g$.
The STAR Collaboration has recently published measurements of the longitudinal double-spin
asymmetry, $A_{LL}$, for inclusive jet and dijet
production at midrapidity in polarized proton-proton collisions at a center-of-mass energy of $\sqrt{s}=510\,$GeV,
based on 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 within the partonic momentum fraction range of $0.015 < x < 0.25$.
The dijet asymmetries are separated into four jet-pair topologies and measured with good precision at low dijet invariant mass, which
provide further constraints on the $x$
dependence of the polarized gluon distribution function.
These recently published midrapidity $A_{LL}$ results will be presented and compared to previous measurements, along with
comparisons to current next-to-leading-order global analyses.
| Submitted on behalf of a Collaboration? | Yes |
|---|---|
| Participate in poster competition? | No |
