Measurement of parity-violating spin asymmetries in W.sup.±./sup. production at midrapidity in longitudinally polarized p+p collisions

0522592 - FZÚ 2020 RIV US eng J - Journal Article
Adare, A. - Aidala, C. - Ajitanand, N.N. - Tomášek, Michal - Vrba, Václav … Total 451 authors
Measurement of parity-violating spin asymmetries in W^± production at midrapidity in longitudinally polarized p+p collisions.
Physical Review D. Roč. 93, č. 5 (2016), s. 1-8, č. článku 051103. ISSN 2470-0010. E-ISSN 2470-0029
Institutional support: RVO:68378271
Keywords : Brookhaven RHIC Coll * PHENIX * STAR * deep inelastic scattering: semi-inclusive reaction * energy: high * helicity * positron * quark
OECD category: Particles and field physics
Impact factor: 4.557, year: 2016
Method of publishing: Limited access
https://doi.org/10.1103/physrevd.93.051103

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. 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.
Permanent Link: http://hdl.handle.net/11104/0307063