XXVIII International Workshop on Deep-Inelastic Scattering and Related Subjects

Measurement of differential cross sections of weak boson production in unpolarized p+p collisions at STAR

Not scheduled

18m

Virtual (Stony Brook, NY)

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

Speaker

Salvatore Fazio (Brookhaven National Laboratory)

Description

We present the status for the measurement of cross sections of weak boson production as a function of the boson's kinematics, by the STAR experiment at RHIC. Results combine data from unpolarized p+p collisions at $\sqrt{s}$ = 500 and 510 GeV collected during the 2011, 2012, 2013, and 2017 runs, corresponding to an integrated luminosity of 700 pb${}^{-1}$. The differential $Z^0$ cross section, measured as a function of the boson's $p_T$, provides important constraints on the energy scale dependence of transverse momentum distributions of partons inside the proton. The $W^{+}/W^{-}$ cross-section ratio as a function of the boson's rapidity is sensitive to the non-pertubative $\overline{d}/\overline{u}$ distribution. The momentum fraction range ($0.1<x<0.3$) covered by these measurements naturally complements the phase space accessed at the LHC, providing critical inputs to global fits.