The production of [Formula: see text] bosons in longitudinally polarized [Formula: see text] collisions is a powerful tool to study the spin-flavor structure of the proton. We report measurements of single- and double-spin asymmetries for [Formula: see text] and [Formula: see text] production in longitudinally polarized proton-proton collisions at [Formula: see text] GeV at RHIC. The single-spin asymmetry results for [Formula: see text] from data sets collected by STAR experiment in 2011 and 2012 provided new constraints on proton’s polarized sea quark distributions and prefer a sizable value for [Formula: see text] polarization. The status for the analysis of a much larger data set collected by STAR in 2013 will also be given.
Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions ats=200 GeV