XXVIII International Workshop on Deep Inelastic Scattering and Related Subjects

Cross section measurements of kinematically reconstructed weak bosons in unpolarized p+p collisions at STAR

25 Mar 2020, 09:50

20m

Brooklyn, NY

Contributed Talk Spin Physics Spin Physics

Speaker

Salvatore Fazio (Brookhaven National Laboratory)

Description

We present cross sections for the weak bosons measured by the STAR experiment at
RHIC in unpolarized proton-proton collisions at $\sqrt{s}$ = 500(510) GeV. The results combine data from run 2011, 2012, and 2013, corresponding to an integrated luminosity of 350~$p{b}^{-1}$. The differential $Z^0$ cross section measured as a function of the boson's $p_T$, provides important constraints on the energy dependence of intrinsic transverse momentum effects of partons inside the proton. The $W^{+}/W^{-}$ cross-section ratio as function of the boson's rapidity, is sensitive to the non-pertubative $\overline{d}/\overline{u}$ distribution. The probed $x$ range ($0.1<x<0.3$) covered by our data naturally complements the phase space accessed at the LHC, providing critical input to global fits.