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Title: Measurement of parity-violating spin asymmetries in W ± production at midrapidity in longitudinally polarized p + p collisions

Abstract

In this article, we present midrapidity measurements from the PHENIX experiment of large parity-violating single-spin asymmetries of high transverse momentum electrons and positrons from W±/Z decays, produced in longitudinally polarized p+p collisions at center of mass energies of √s=500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parity-violating nature of the W-boson coupling to quarks and antiquarks. 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. In addition, these high Q2 data probe the parton structure of the proton at W mass scale and provide an important addition to our understanding of the antiquark parton helicity distribution functions at an intermediate Bjorken x value of roughly MW/√s=0.16.

Authors:
 [1]
  1. Univ. of Colorado, Boulder, CO (United States).et al
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Contributing Org.:
PHENIX Collaboration
OSTI Identifier:
1324118
Alternate Identifier(s):
OSTI ID: 1243007; OSTI ID: 1335476
Report Number(s):
BNL-112149-2016-JA
Journal ID: ISSN 2470-0010; KB0201022; ERKBP09
Grant/Contract Number:  
AC05-00OR22725; SC00112704
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 93; Journal Issue: 5; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; midrapidity; spin asymmetries; Relativistic Heavy Ion Collider

Citation Formats

Adare, A. Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions. United States: N. p., 2016. Web. doi:10.1103/PhysRevD.93.051103.
Adare, A. Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions. United States. doi:10.1103/PhysRevD.93.051103.
Adare, A. Wed . "Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions". United States. doi:10.1103/PhysRevD.93.051103. https://www.osti.gov/servlets/purl/1324118.
@article{osti_1324118,
title = {Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p+p collisions},
author = {Adare, A.},
abstractNote = {In this article, we present midrapidity measurements from the PHENIX experiment of large parity-violating single-spin asymmetries of high transverse momentum electrons and positrons from W±/Z decays, produced in longitudinally polarized p+p collisions at center of mass energies of √s=500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parity-violating nature of the W-boson coupling to quarks and antiquarks. 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. In addition, these high Q2 data probe the parton structure of the proton at W mass scale and provide an important addition to our understanding of the antiquark parton helicity distribution functions at an intermediate Bjorken x value of roughly MW/√s=0.16.},
doi = {10.1103/PhysRevD.93.051103},
journal = {Physical Review D},
number = 5,
volume = 93,
place = {United States},
year = {2016},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 9 works
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Figures / Tables:

FIG. 1. FIG. 1.: (color online). (Upper panels) Spectra for (a) e+ and (b) e using the EMCal for momentum determination from p+p collisions at $\sqrt{s}$ = 510 GeV from 2013. From top to bottom, the curves are: solid [red] is the sum between background and signal; shaded band [orange] is themore » background estimation with the uncertainty from the GPR method; dashed [dark blue] is the W±/Z → e± signal obtained from simulation normalized to the data; and solid [light blue] is the contribution from Z → e+e. (Lower panels) Point-by-point comparison of the data and the fit result: (data$i$-fit)/σ$i$, where σ$i$ is statistical uncertainty of the $i$-th data point.« less

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Works referenced in this record:

Measurement of the Parity-Violating Longitudinal Single-Spin Asymmetry for W ± Boson Production in Polarized Proton-Proton Collisions at s = 500 GeV
journal, February 2011


Cross Section and Parity-Violating Spin Asymmetries of W ± Boson Production in Polarized p + p Collisions at s = 500 GeV
journal, February 2011


PHENIX calorimeter
journal, March 2003

  • Aphecetche, L.; Awes, T. C.; Banning, J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 499, Issue 2-3
  • DOI: 10.1016/S0168-9002(02)01954-X

Parton distributions and parity-violating asymmetries in W± and Z production at RHIC
journal, September 1993


Evidence for Polarization of Gluons in the Proton
journal, July 2014


Extraction of spin-dependent parton densities and their uncertainties
journal, August 2009


Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering
journal, January 2005


Single-spin asymmetries in W boson production at next-to-leading order
journal, May 2015


Prospects for Spin Physics at RHIC
journal, December 2000

  • Bunce, Gerry; Saito, Naohito; Soffer, Jacques
  • Annual Review of Nuclear and Particle Science, Vol. 50, Issue 1
  • DOI: 10.1146/annurev.nucl.50.1.525

Impact of CLAS and COMPASS data on polarized parton densities and higher twist
journal, April 2007

  • Leader, Elliot; Sidorov, Aleksander V.; Stamenov, Dimiter B.
  • Physical Review D, Vol. 75, Issue 7
  • DOI: 10.1103/PhysRevD.75.074027

PYTHIA 6.4 physics and manual
journal, May 2006


Inclusive double-helicity asymmetries in neutral-pion and eta-meson production in p + p collisions at s = 200 GeV
journal, July 2014


Single-spin physics with weak bosons at RHIC
journal, August 2003


PHENIX on-line and off-line computing
journal, March 2003

  • Adler, S. S.; Chujo, T.; Desmond, E. J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 499, Issue 2-3
  • DOI: 10.1016/S0168-9002(02)01958-7

Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at s = 200 GeV
journal, August 2015


PHENIX detector overview
journal, March 2003

  • Adcox, K.; Adler, S. S.; Aizama, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 499, Issue 2-3
  • DOI: 10.1016/S0168-9002(02)01950-2

Measurement of the deuteron spin structure function g1d(x) for 1 (GeV/c)2<Q2<40 (GeV/c)2
journal, September 1999


Spin asymmetries A 1 and structure functions g 1 of the proton and the deuteron from polarized high energy muon scattering
journal, October 1998


The g1 problem: Deep inelastic electron scattering and the spin of the proton
journal, June 1990


Determination of polarized parton densities from a QCD analysis of inclusive and semi-inclusive deep inelastic scattering data
journal, December 2010

  • Leader, Elliot; Sidorov, Aleksander V.; Stamenov, Dimiter B.
  • Physical Review D, Vol. 82, Issue 11
  • DOI: 10.1103/PhysRevD.82.114018

Quark helicity distributions from longitudinal spin asymmetries in muon–proton and muon–deuteron scattering
journal, October 2010


A first unbiased global determination of polarized PDFs and their uncertainties
journal, October 2014


Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at RHIC
journal, August 2014


The spin-dependent structure function of the proton <mml:math altimg="si1.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:msubsup><mml:mi>g</mml:mi><mml:mn>1</mml:mn><mml:mi>p</mml:mi></mml:msubsup></mml:math> and a test of the Bjorken sum rule
journal, July 2010


Helicity parton distributions from spin asymmetries in W -boson production at RHIC
journal, May 2010


The polarised valence quark distribution from semi-inclusive DIS
journal, March 2008


    Works referencing / citing this record:

    The spin structure of the nucleon
    journal, June 2019

    • Deur, Alexandre; Brodsky, Stanley J.; de Téramond, Guy F.
    • Reports on Progress in Physics, Vol. 82, Issue 7
    • DOI: 10.1088/1361-6633/ab0b8f

    The spin structure of the nucleon
    journal, June 2019

    • Deur, Alexandre; Brodsky, Stanley J.; de Téramond, Guy F.
    • Reports on Progress in Physics, Vol. 82, Issue 7
    • DOI: 10.1088/1361-6633/ab0b8f

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