Measurement of the parity-violating longitudinal single-spin asymmetry $A_{L}$ for $W^{-(+)}$ boson production in polarized proton collisions at $\sqrt{s}=510$ GeV at RHIC

The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions to gain a deeper insight into the spin structure and dynamics of the proton. The collision of polarized protons at $\sqrt{s}=500\,$GeV opened a new era of spin-flavor structure studies using the production of $W^{-(+)}$ bosons which are primarily produced in $\bar{u}+d\,(\bar{d}+u)$ collisions. The STAR experiment is well equipped to measure $W^{-(+)} \rightarrow e^{-}+ \bar{\nu}_{e}\,(e^{+}+ \nu_{e})$ in longitudinally polarized proton collisions. The published STAR $A_L$ results (combination of 2011 and 2012 data) have been used by two global analyses groups suggesting a significant impact in constraining the helicity distributions of anti-$u$ and anti-$d$ quarks. In 2013, the STAR experiment collected a data set at $\sqrt{s}=510$ GeV with a factor of three larger figure of merit based on a total integrated luminosity of $\sim$300 pb$^{-1}$ and an average beam polarization of $\sim$54\%. We will report on the status of the STAR 2013 W $A_L$ analysis along with future plans.