The spin structure function g(1)(p) of the proton and a test of the Bjorken sum rulecf

0465613 - ÚPT 2017 RIV NL eng J - Journal Article
Adolph, C. - Akhunzyanov, R. - Alexeev, M. - Alexeev, G. D. - Amoroso, A. - Andrieux, V. - Anosov, V. - Austregisilio, A. - Azevedo, C. - Badelek, B. - Balestra, F. - Barth, J. - Baum, G. - Beck, R. - Bedfer, Y. - Bernhard, J. - Bicker, K. - Bielert, E. R. - Birsa, R. - Bisplinghoff, J. - Bodlak, M. - Boer, M. - Bordalo, P. - Bradamante, F. - Braun, C. - Bressan, A. - Büchele, M. - Burtin, E. - Capozza, L. - Chang, W.-C. - Chiosso, M. - Choi, I. - Chung, S.U. - Cicuttin, A. - Crespo, M. - Curiel, Q. - Dalla Torre, S. - Dasgupta, S. S. - Dasgupta, S. - Denisov, O. - Dhara, L. - Donskov, S. - Doshita, N. - Duic, V. - Dziewiecki, M. - Efremov, A.V. - Eversheim, P. - Eyrich, W. - Ferrero, A. - Finger, M. - Finger jr., M. - Fischer, H. - Franco, C. - Fresne von Hohenesche, N. - Friedrich, J. - Frolov, V. - Fuchey, E. - Gautheron, F. - Gavrichtchouk, O. - Gerassimov, S. - Giordano, F. - Gnesi, I. - Gorzellik, M. - Grabmüller, S. - Grasso, A. - Grosse-Perdekapm, M. - Grube, B. - Grussenmeyer, T. - Guskov, A. - Haas, F. - Hahne, D. - von Harrach, D. - Hashimoto, R. - Heinsius, F. - Herrmann, F. - Hinterberger, F. - Horikawa, N. - d'Hose, N. - Hsieh, C.-Yu. - Huber, S. - Ishimoto, S. - Ivanov, A. - Ivanshin, Yu. - Iwata, T. - Jahn, R. - Jary, V. - Jörg, P. - Joosten, R. - Kabuss, E. - Ketzer, B. - Khaustov, G. - Khokhlov, Y. - Kisselev, Y. - Klein, F. - Klimaszewski, K. - Koivuniemi, J. - Kolosov, V. - Kondo, K. - Königsmann, K. - Konorov, I. - Konstantinov, V. - Kotzinian, A. - Kouznetsov, O. - Krämer, M. - Kremser, P. - Krinner, F. - Kroumchtein, Z. - Kuchinski, N. - Kunne, F. - Kurek, K. - Kurjata, R. P. - Lednev, A. - Lehmann, A. - Levillain, M. - Levorato, S. - Lichtenstadt, J. - Longo, R. - Maggiora, A. - Magnon, A. - Makins, N. - Makke, N. - Mallot, G. - Marchand, C. - Martin, A. - Marzec, J. - Matoušek, J. - Matsuda, H. - Matsuda, T. - Meshcheryakov, G. - Meyer, W. - Michigami, T. - Mikhailov, Y. - Miyachi, Y. - Nagaytsev, A. - Nagel, T. - Nerling, F. - Neyret, D. - Nikolaenko, V. - Nový, J. - Nowak, W. D. - Nunes, A.S. - Olshevsky, A. - Orlov, I. - Ostrick, M. - Panzieri, D. - Parsamyan, B. - Paul, S. - Peng, J.-C. - Pereira, F. - Pešek, M. - Peshekhonov, D. - Platchkov, S. - Pochodzalla, J. - Polyakov, V. - Pretz, J. - Quaresma, M. - Quintans, C. - Ramos, S. - Regali, C. - Reicherz, G. - Riedl, C. - Rocco, E. - Rossiyskaya, N. S. - Ryabchikov, D. - Rychter, A. - Samoylenko, V. - Sandacz, A. - Santos, H. - Sarkar, S. - Savin, I. - Sbrizzai, G. - Schiavon, P. - Schmidt, K. - Schmieden, H. - Schönning, K. - Schopferer, S. - Selyunin, A. - Shevchenko, O. - Silva, L. - Sinha, L. - Sirtl, S. - Slunecka, M. - Sozzi, F. - Srnka, Aleš - Stolarski, M. - Sulc, M. - Suzuki, H. - Szabelski, A. - Szameitat, T. - Sznajder, P. - Takekawa, S. - Ter Wolbeek, J. - Tessaro, S. - Tessarotto, F. - Thibaud, F. - Tosello, F. - Tskhay, V. - Uhl, S. - Veloso, J. - Virius, M. - Weisrock, T. - Wilfert, M. - Windmolders, R. - Zaremba, K. - Zavertyaev, M. - Zemlyanichkina, E. - Ziembicki, M. - Zink, A.
The spin structure function g(1)(p) of the proton and a test of the Bjorken sum rulecf.
Physics Letters. B. Roč. 753, FEB 10 (2016), s. 18-28. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT(CZ) LO1212
Institutional support: RVO:68081731
Keywords : deep-inelastic-scattering * dependent structure-function * parton distributions
Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders
Impact factor: 4.807, year: 2016

New results for the double spin asymmetry A(1)(p) and the proton longitudinal spin structure function g(1)(p) are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 target. The data were collected in 2011 and complement those recorded in 2007 at 160 GeV, in particular at lower values of x. They improve the statistical precision of g(1)(p)(x) by about a factor of two in the region x less than or similar to 0.02. A next-to-leading order QCD fit to the g(1) world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, Delta Sigma, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g(1)(p). The uncertainty of Delta Sigma is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g(1)(NS) (x, Q(2)) yields as ratio of the axial and vector coupling constants vertical bar gA/gV vertical bar = 1.22 +/- 0.05 (stat.) +/- 0.10 (syst.), which validates the sum rule to an accuracy of about 9 percent.
Permanent Link: http://hdl.handle.net/11104/0264296