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

Abstract

We report on the $W$ and $Z/{\gamma }^{\ast }$ differential and total cross sections as well as the $W^{+}$/$W^{-}$ and $(W^{+}+W^{-})$/$(Z/{\gamma }^{\ast })$ cross-section ratios measured by the STAR experiment at RHIC in $p+p$ collisions at $\sqrt{s}=500$ GeV and $510$ GeV. The cross sections and their ratios are sensitive to quark and antiquark parton distribution functions. In particular, at leading order, the $W$ cross-section ratio is sensitive to the $\bar{d}/\bar{u}$ ratio. These measurements were taken at high $Q^2\sim M_W^2,M_Z^2$ and can serve as input into global analyses to provide constraints on the sea quark distributions. The results presented here combine three STAR data sets from 2011, 2012, and 2013, accumulating an integrated luminosity of 350 pb${}^{-1}$. We also assess the expected impact that our $W^{+}/W^{-}$ cross-section ratios will have on various quark distributions, and find sensitivity to the $\bar{u}-\bar{d}$ and $\bar{d}/\bar{u}$ distributions.

Accepted to PRD 39 pages, 15 Figs., and 9 tables

References in corpus (13)

• PYTHIA 6.4 Physics and Manual
• New parton distributions for collider physics
• LHAPDF6: parton density access in the LHC precision era
• Parton distributions in the LHC era: MMHT 2014 PDFs
• Determination of the strange quark density of the proton from ATLAS measurements of the W->l nu and Z->ll cross sections
• Measurement of the W Boson Mass with the D0 Detector
• Measurement of the shape of the boson transverse momentum distribution in ppbar -> Z/gamma* -> ee+X events produced at sqrt{s}=1.96 TeV
• Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC
• Cross Section and Parity Violating Spin Asymmetries of W^+/- Boson Production in Polarized p+p Collisions at sqrt(s)=500 GeV
• Transverse momentum cross section of $e^{+}{e}^{-}$ pairs in the $Z$-boson region from $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV
• Measurement of the parity-violating longitudinal single-spin asymmetry for $W^{\pm }$ boson production in polarized proton-proton collisions at $\sqrt{s}=500$GeV
• Helicity Parton Distributions from Spin Asymmetries in W-Boson Production at RHIC
• Review of single vector boson production in pp collisions at $\sqrt{s}=7$ TeV

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• Light quark and antiquark constraints from new electroweak data
• Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in $p+p$ and $p+d$ collisions at 120 GeV
• Exclusive $J/\psi$, $\psi (2s)$, and $e^{+}{e}^{-}$ pair production in Au$+$Au ultra-peripheral collisions at RHIC
• Extraction of the neutron F2 structure function from inclusive proton and deuteron deep-inelastic scattering data
• Probing nucleon spin structure in deep-inelastic scattering, proton-proton collisions and Drell-Yan processes
• Bayesian Monte Carlo extraction of sea asymmetry with SeaQuest and STAR data
• Probing the gluonic structure of the deuteron with $J/\psi$ photoproduction in d+Au ultra-peripheral collisions