Measurement of parity-violating spin asymmetries in W${}^{\pm }$ production at midrapidity in longitudinally polarized $p$$+$$p$ collisions

Abstract

We present measurements from the PHENIX experiment of large parity-violating single spin asymmetries of high transverse momentum electrons and positrons from $W^{\pm }/Z$ decays, produced in longitudinally polarized $p$$+$$p$ collisions at center of mass energies of $\sqrt{s}$=500 and 510~GeV. These asymmetries allow direct access to the anti-quark polarized parton distribution functions due to the parity-violating nature of the $W$-boson coupling to quarks and anti-quarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb${}^{-1}$, which exceeds previous PHENIX published results by a factor of more than 27. These high $Q^2$ data provide an important addition to our understanding of anti-quark parton helicity distribution functions.

451 authors, 8 pages, 3 figures, 2 tables. v2 is version accepted by Phys. Rev. D for publication as a Rapid Communication. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.html

References in corpus (11)

• PYTHIA 6.4 Physics and Manual
• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• A first unbiased global determination of polarized PDFs and their uncertainties
• Evidence for polarization of gluons in the proton
• The Polarised Valence Quark Distribution from semi-inclusive DIS
• Impact of CLAS and COMPASS data on Polarized Parton Densities and Higher Twist
• 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
• 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
• Single-Spin Asymmetries in W Boson Production at Next-to-Leading Order

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