W Boson Production in Polarized p+p Collisions at STAR

Justin Stevens

Indiana University
The production of W bosons in p+p collisions at RHIC provides an excellent tool to probe the flavor-dependence of the sea quark distributions of the proton. In particular, parity-violating single-spin asymmetries for W bosons produced in longitudinally polarized p+p collisions give access to the flavor-separated light quark and antiquark polarization distributions. Precise measurements of the flavor-separated antiquark polarizations are expected to place additional constraints on models and further our understanding of the mechanism responsible for generating the light quark sea of the proton, complementary to measurements of the $\bar{d}/\bar{u}$ flavor asymmetry in fixed target Drell-Yan. The W bosons produced in the polarized p+p collisions can be detected through their electron decay channel where only the charged lepton is observed. The large acceptance of the STAR Time Projection Chamber and Electromagnetic Calorimeters is well suited to reconstruct the decay electrons and separate the signal from the large QCD background, yielding a clean W signal. Results for the W boson production cross section and parity-violating single-spin asymmetry, as well as future projections for the STAR W spin program, will be presented.