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.

arXiv commentAccepted to PRD 39 pages, 15 Figs., and 9 tables

References in corpus (49)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The anti-k_t jet clustering algorithm
• New parton distributions for collider physics
• LHAPDF6: parton density access in the LHC precision era
• Parton distributions from high-precision collider data
• New parton distribution functions from a global analysis of quantum chromodynamics
• Parton distributions in the LHC era: MMHT 2014 PDFs
• Precision Electroweak Measurements on the Z Resonance
• Tuning Monte Carlo Generators: The Perugia Tunes
• Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP
• The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
• The CT10 NNLO Global Analysis of QCD
• Improved Measurement of the $\bar{d}/\bar{u}$ Asymmetry in the Nucleon Sea
• Combining QCD and electroweak corrections to dilepton production in FEWZ
• Constraints on large-$x$ parton distributions from new weak boson production and deep-inelastic scattering data
• Measurement of the Inclusive W and Z Production Cross Sections in pp Collisions at sqrt(s) = 7 TeV
• Measurements of Inclusive W and Z Cross Sections in pp Collisions at sqrt(s)=7 TeV
• Measurements of Inclusive W and Z Cross Sections in p-pbar Collisions at sqrt{s} =1.96 TeV
• Precision measurement and interpretation of inclusive $W^{+}$, $W^{-}$ and $Z/{\gamma }^{\ast }$ production cross sections with the ATLAS detector
• Measurement of $W^{\pm }$ and $Z$-boson production cross sections in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Determination of the strange quark density of the proton from ATLAS measurements of the W->l nu and Z->ll cross sections
• Reweighting NNPDFs: the W lepton asymmetry
• Measurement of the W Boson Mass with the D0 Detector
• Precise measurement of the W-boson mass with the CDF II detector
• A statistical approach for polarized parton distributions
• Measurement of the W -> lnu and Z/gamma* -> ll production cross sections in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS 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
• Extraction of the Width of the W Boson from Measurements of sigma(ppbar->W+X)B(W->e nu) and sigma(ppbar->Z+X)B(Z->e e) and their Ratio
• Strange quark suppression from a simultaneous Monte Carlo analysis of parton distributions and fragmentation functions
• Measurement of the transverse single-spin asymmetry in $p^{\uparrow }+p\to W^{\pm }/Z^0$ at RHIC
• 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
• W and Z Boson Production in PbarP Collisions at Sqrt(s)=1.8 TeV
• Parton Distributions from W+- and Z Production in Polarized pp and pn Collisions at RHIC
• 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 $\sigma \cdot B(W\to e\nu )$ and $\sigma \cdot B(Z^0\to e^{+}{e}^{-})$ in $p\bar{p}$ collisions at $\sqrt{s}=1.8$ 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
• New developments in the statistical approach of parton distributions: tests and predictions up to LHC energies
• Helicity Parton Distributions from Spin Asymmetries in W-Boson Production at RHIC
• Reconstruction of Monte Carlo replicas from Hessian parton distributions
• Measurement of parity-violating spin asymmetries in W${}^{\pm }$ production at midrapidity in longitudinally polarized $p$$+$$p$ collisions
• Measurements of $W$ and $Z$ boson production in $pp$ collisions at $\sqrt{s}=5.02$ TeV with the ATLAS detector
• Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at $\sqrt{s}$ = 510 GeV
• Measurement of W and Z boson production cross sections
• Measurement of the $W\to e\nu$ and $Z/{\gamma }^{\ast }\to e^{+}{e}^{-}$ Production Cross Sections at Mid-rapidity in Proton-Proton Collisions at $\sqrt{s}$ = 500 GeV
• Cross section and longitudinal single-spin asymmetry $A_L$ for forward $W^{\pm }\to {\mu }^{\pm }\nu$ production in polarized $p$$+$$p$ collisions at $\sqrt{s}=510$ GeV
• Review of single vector boson production in pp collisions at $\sqrt{s}=7$ TeV
• Statistical description of the flavor structure of the nucleon sea

Cited by in corpus (11)

• 50 Years of Quantum Chromodynamics
• The Present and Future of QCD
• Isovector EMC effect from global QCD analysis with MARATHON data
• Observation of strong nuclear suppression in exclusive $J/\psi$ photoproduction in Au$+$Au ultra-peripheral collisions at RHIC
• 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