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

15 Apr 2021, 11:30
20m
Virtual (Stony Brook, NY)

Virtual

Stony Brook, NY

Online
Contributed Talk Structure Functions and Parton Densities Structure function and parton densities

Speaker

Jae Nam (Temple University)

Description

While the unpolarized valence quark ($d$ and $u$) distributions 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, are sensitive to the $\bar{d}/\bar{u}$ ratio at leading order at a large $Q^2$ set by the $W$ mass. This talk will discuss the recently published $W$ and $Z/\gamma^*$ cross section measurements via lepton-decay tagging, using the STAR $pp$ collision data at a center-of-mass energy of $\sqrt{s} = 510\,\mathrm{GeV}$ collected during the years 2011-2013, corresponding to an integrated luminosity of $350\,\mathrm{pb^{-1}}$. A status update will be given on an analysis based on an additional data set at $\sqrt{s} = 510\,\mathrm{GeV}$ collected in 2017, corresponding to an integrated luminosity of $350\,\mathrm{pb^{-1}}$.

Primary author

Jae Nam (Temple University)

Presentation materials