Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at STAR

The production of W-+/- bosons in longitudinally polarized p + p collisions is a powerful tool to study the spin-flavor structure of the proton. We report measurements of single- and double-spin asymmetries for W and Z/gamma* production in longitudinally polarized proton-proton collisions at root s = 510 GeV at RHIC. The single-spin asymmetry results for W-+/- 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 (u) over bar polarization. The status for the analysis of a much larger data set collected by STAR in (C) 2013 will also be given.