Speaker
Description
The production of $W$ bosons in longitudinally polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) provides an ideal tool to study the spin-flavor structure of the proton, through the measurement of the parity-violating single-spin asymmetry, $A_L$. STAR has measured $A_L$ for $W$ boson production from datasets taken in 2011 and 2012 which provided significant constraints on the helicity distribution functions of $\bar u$ and $\bar d$ quarks. In 2013 the STAR experiment collected a large data sample of 250 pb$^{-1}$ which is about three times larger than the total integrated luminosity from previous years. The final $A_L$ results from the 2013 STAR data sample will be reported along with the combined results from the 2011--2013 data sets, and the impact of these results on the light sea quark helicity distribution functions.
