Achievements and open issues in the determination of polarized parton distribution functions

Abstract

I review the current status of the determination of helicity-dependent, or polarized, parton distribution functions from a comprehensive analysis of experimental data in perturbative quantum chromodynamics. I illustrate the latest achievements driven by new measurements in polarized proton-proton collisions at the Relativistic Heavy Ion Collider, namely the first evidence of a sizable polarized light sea quark asymmetry and of a positive polarized gluon distribution in the proton. I discuss which are the open issues in the determination of polarized distributions, and how these may be addressed in the future by ongoing, planned and proposed experimental programs.

8 pages, 2 figures, to appear in the proceedings of the 21st International Symposium on Spin Physics (SPIN2014)

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Cited by in corpus (2)

• Longitudinal Double-Spin Asymmetries for ${\pi }^0$s in the Forward Direction for 510 GeV Polarized $pp$ Collisions
• Can sea quark asymmetry shed light on the orbital angular momentum of the proton?