2005/11/10 by E.S. Ageev, COMPASS Collaboration, V. Alexakhin +98 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1016/j.physletb.2005.11.049
published as Phys.Lett.B633:25-32,2006 · 10 pages, 3 figures
arxiv created 2005/11/10 · openalex publication_date 2005/11/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We present a determination of the gluon polarization Δ G / G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q 2 < 1 ( GeV / c ) 2 , with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6 LiD target. The helicity asymmetry for the selected events is 〈 A ∥ / D 〉 = 0.002 ± 0.019 ( stat ) ± 0.003 ( syst ) . From this value, we obtain in a leading-order QCD analysis Δ G / G = 0.024 ± 0.089 ( stat ) ± 0.057 ( syst ) at x g = 0.095 and μ 2 ≃ 3 ( GeV / c ) 2 .