Campus Units

Physics and Astronomy

Document Type

Article

Publication Date

2-11-2011

Journal or Book Title

Physical Review Letters

Volume

106

Issue

6

First Page

062001

DOI

10.1103/PhysRevLett.106.062001

Abstract

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = 0.86(-0.14)(+0.30) and Ae(L)(e-) = 0.88(-0.71)(+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p + p collisions at a center-of-mass energy of root s = 500 GeV with the PHENIX detector at RHIC. These e(+/-) come mainly from the decay of W-+/- and Z(0) bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W-+/- to the light quarks. The observed electron and positron yields were used to estimate W-+/- boson production cross sections for the e(+/-) channels of sigma(pp -> W+X) X BR(W+ -> e(+) nu(e)) = 144.1 +/- 21.2(stat)(-10.3)(+3.4)(syst) +/- 21.6(norm) pb, and sigma(pp -> W-X) X BR(W- -> e(-) (nu) over bar (e)) = 3.17 +/- 12.1(stat)(-8.2)(+10.1)(syst) +/- 4.8(norm) pb.

Comments

This article is published as Adare, A., S. Afanasiev, C. Aidala, N. N. Ajitanand, Y. Akiba, R. Akimoto, J. Alexander et al. "Cross section and parity-violating spin asymmetries of W±boson production in polarized p+ p collisions at s= 500 GeV." Physical review letters 106, no. 6 (2011): 062001. DOI:10.1103/PhysRevLett.106.062001. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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