The spin-dependent structure function of the proton g1p and a test of the Bjorken sum rule

Journal Article (Journal Article)

The inclusive double-spin asymmetry, A1p, has been measured at COMPASS in deep-inelastic polarised muon scattering off a large polarised NH3 target. The data, collected in the year 2007, cover the range Q2 > 1 (GeV / c)2, 0.004 < x < 0.7 and improve the statistical precision of g1p (x) by a factor of two in the region x < 0.02. The new proton asymmetries are combined with those previously published for the deuteron to extract the non-singlet spin-dependent structure function g1NS (x, Q2). The isovector quark density, Δ q3 (x, Q2), is evaluated from a NLO QCD fit of g1NS. The first moment of Δ q3 is in good agreement with the value predicted by the Bjorken sum rule and corresponds to a ratio of the axial and vector coupling constants | gA / gV | = 1.28 ± 0.07 (stat .) ± 0.10 (syst.). © 2010 Elsevier B.V. All rights reserved.

Full Text

Duke Authors

Cited Authors

  • Alekseev, MG; Alexakhin, VY; Alexandrov, Y; Alexeev, GD; Amoroso, A; Austregesilo, A; Badełek, B; Balestra, F; Ball, J; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, MP; Chaberny, D; Čotić, D; Chiosso, M; Chung, SU; Cicuttin, A; Colantoni, M; Crespo, ML; Torre, SD; Das, S; Dasgupta, SS; Denisov, OY; Dhara, L; Diaz, V; Donskov, SV; Doshita, N; Duic, V; Dünnweber, W; Efremov, A; El Alaoui, A; Eversheim, PD; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Fischer, H; Franco, C; Friedrich, JM; Garfagnini, R; Gautheron, F; Gavrichtchouk, OP; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmüller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; von Harrach, D; Hasegawa, T; Heinsius, FH; Hermann, R; Herrmann, F; Heß, C; Hinterberger, F; Horikawa, N; Höppner, C; d'Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Y; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuß, E; Käfer, W; Kang, D; Ketzer, B; Khaustov, GV; Khokhlov, YA; Kisselev, Y; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, JH; Kolosov, VN

Published Date

  • July 5, 2010

Published In

Volume / Issue

  • 690 / 5

Start / End Page

  • 466 - 472

International Standard Serial Number (ISSN)

  • 0370-2693

Digital Object Identifier (DOI)

  • 10.1016/j.physletb.2010.05.069

Citation Source

  • Scopus