Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at √ s = 510 GeV
Physical Review D
We report new STAR measurements of the single-spin asymmetries AL for W+ and W− bosons produced in polarized proton-proton collisions at √s=510 GeV as a function of the decay-positron and decay-electron pseudorapidity. The data were obtained in 2013 and correspond to an integrated luminosity of 250 pb−1. The results are combined with previous results obtained with 86 pb−1. A comparison with theoretical expectations based on polarized lepton-nucleon deep-inelastic scattering and prior polarized proton-proton data suggests a difference between the ¯u and ¯d quark helicity distributions for 0.05
STAR Collaboration; Gibson, Adam; and Stanislaus, Shrivel, "Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at √ s = 510 GeV" (2019). Physics and Astronomy Faculty Publications. 189.