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Inclusive Jet Measurements in Longitudinally Polarized proton-proton Collisions at STAR

High Energy Physics - Experiment 2019-09-27 v1 Nuclear Experiment

Abstract

Jet production in high energy proton-proton (p+pp+p) collisions is dominated by hard QCD subprocesses such as gluon-gluon and quark-gluon scatterings. Therefore p+pp+p is an effective tool to probe the internal distribution of gluons in the proton. The STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC) is using longitudinally polarized p+pp+p collisions at the center of mass energies, s=\sqrt{s} = 200 and 510 GeV, to study the cross-section and double spin asymmetries, ALLA_{LL}, of inclusive jet and di-jet production. The measurements at s=\sqrt{s} = 200 GeV showed that the jet cross-sections are well described by the next-to-leading-order perturbative QCD calculations after underlying event and hadronization corrections. The previous 2009 s=\sqrt{s} = 200 GeV inclusive jet asymmetry ALLA_{LL} measurement at pseudo-rapidity η<|\eta| < 1.0 showed the first experimental evidence of a non-zero gluon polarization for partonic momentum fraction, x>0.05x > 0.05. The inclusive jet ALLA_{LL} measurement at s=\sqrt{s} = 510 GeV allows to explore the gluon polarization to smaller x0.02x \sim 0.02. The 2012 inclusive jet ALLA_{LL} and cross-section measurements at s=\sqrt{s} = 510 GeV, the techniques used in the jet analysis including underlying event correction, and future perspectives related to jet measurements at STAR will be presented.

Keywords

Cite

@article{arxiv.1909.12259,
  title  = {Inclusive Jet Measurements in Longitudinally Polarized proton-proton Collisions at STAR},
  author = {Zilong Chang},
  journal= {arXiv preprint arXiv:1909.12259},
  year   = {2019}
}