Measurements of $W$ and $Z/{\gamma }^{\ast }$ cross sections and their ratios in $pp$ collisions at STAR

Abstract

While the unpolarized parton distribution functions of the valence quarks ($d$ and $u$) are well determined from DIS experiments, the sea quark counterparts, $\bar{d}$ and $\bar{u}$, are much less constrained, in particular, near the valence region. Measurements of $W^{+}/W^{-}$ production ratio in $pp$ collider experiments, such as the STAR experiment at RHIC, can probe the $\bar{d}/\bar{u}$ ratio at a large $Q^2$ set by the $W$ mass. These proceedings will discuss recent results of $W$ and $Z$ cross-section measurements using the STAR $pp$ collision data at a center-of-mass energy of $\sqrt{s}=500/510\mathrm{GeV}$ collected in 2011, 2012, 2013 and 2017.

arXiv commentProceedings for the XXVIII International Workshop on Deep-Inelastic Scattering and Related Subjects Comments: changed the aspect ratio of the picture on the right panel of Figure 3 as per a request made by the editor (Feb 14, 2022)