Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Measurement of the parity-violating longitudinal single-spin asymmetry for W+- boson production in polarized proton-proton collisions at sqrt s = 500 GeV

Journal Article · · Physical Review Letters
We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W{sup +} and W{sup -} boson production in longitudinally polarized proton-proton collisions at {radical}s = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A{sub L}{sup W+} = -0.27 {+-} 0.10(stat.) {+-} 0.02(syst.) {+-} 0.03(norm.) and A{sub L}{sup W-} = 0.14 {+-} 0.19(stat.) {+-} 0.02(syst.) {+-} 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.
Research Organization:
Brookhaven National Laboratory (BNL) Relativistic Heavy Ion Collider
Sponsoring Organization:
DOE - OFFICE OF SCIENCE
DOE Contract Number:
AC02-98CH10886
OSTI ID:
1021403
Report Number(s):
BNL--94199-2011-JA; KB0202012
Journal Information:
Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 6 Vol. 106; ISSN 0031-9007; ISSN PRLTAO
Country of Publication:
United States
Language:
English