Speaker
Dr
Matthew Posik
(Temple University)
Description
Over the past several years the STAR experiment at RHIC has been contributing to our understanding of the proton structure. Through proton-proton collisions, STAR is well equipped to measure the e$^{\pm}$ leptonic decays of $W^{\pm}$ bosons in the mid-rapidity region (-1.1 $\le \eta \le $ 1.1) at $\sqrt{s}$ = 500/510 GeV. The $W$ cross section ratio ($W^+/W^-$) is sensitive to unpolarized $u$, $d$, $\bar{u}$, and $\bar{d}$ quark distributions. At these kinematics STAR is able to measure the quark distributions near Bjorken-x of 0.1. The RHIC runs in 2012 and 2013 at $\sqrt{s}$ = 500/510 GeV saw a significant increase in delivered luminosity from previous years. This resulted in using data samples of about 80 and 250 pb$^{-1}$ of integrated luminosity, respectively. The increased statistics will lead to a higher precision measurement of the $W^{+}/W^{-}$ cross section ratio as well as its $\eta$ dependence at mid-rapidity. Presented here is an update of the $W$ cross section ratio analysis from the STAR 2012 and 2013 runs.
Author
Dr
Matthew Posik
(Temple University)
