  I study the impact of recent measurements performed at the Relativistic Heavy
Ion Collider on the determination of helicity-dependent parton distribution
functions of the proton. Specifically, I consider: preliminary data on
longitudinally single-spin asymmetries for $W$-boson production recorded by the
STAR experiment during the 2013 run at a center-of-mass energy $\sqrt{s}=510$
GeV; data on longitudinally double-spin asymmetries for di-jet production
recorded by the STAR experiment during the 2009 run at $\sqrt{s}=200$ GeV; and
data on longitudinally double-spin asymmetries for neutral pion production
recorded by the PHENIX experiment during a series of runs between 2006 and 2013
at $\sqrt{s}=200$ GeV and $\sqrt{s}=510$ GeV. The impact of the new data is
studied by applying Bayesian reweighting to NNPDFpol1.1, the most recent global
analysis of helicity-dependent parton distribution functions based on the NNDPF
methodology. In comparsion to NNDPFpol1.1, a slightly more positive polarized
gluon PDF, extended to somewhat smaller values of momentum fractions with
narrower uncertainties, as well as a slightly more marked and more precise
asymmetry between polarized up and down sea quarks are found in this study.

High Energy Physics - Phenomenology