Probing Gluon Helicity with Dijets from √s = 510 GeV Polarized Proton Collisions at STAR

Apr 13, 2016, 12:00 PM
SR4a (DESY Hamburg)


DESY Hamburg

Spin Physics WG6 Spin Physics


Suvarna Ramachandran (STAR Collaboration, University of Kentucky)


The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry (A_LL) is sensitive to the polarized parton distributions and may be used to extract information about the gluon helicity contribution (ΔG) to the spin of the proton. Previous STAR jet measurements at √s = 200 GeV show evidence of polarized gluons for gluon momentum fractions above 0.05. The measurement of dijet A_LL at √s = 510 GeV will extend the current constraints on ΔG to lower gluon momentum fractions and allow for the reconstruction of the partonic kinematics at leading order. Preliminary results from the dijet A_LL measurements from ~80 pb^(-1) of ~53% polarized proton data taken during the 2012 RHIC run will be presented.

Primary author

Suvarna Ramachandran (STAR Collaboration, University of Kentucky)

Presentation materials