Leading order determination of the gluon polarisation from DIS events with high-pThadron pairs

Autor: S. Koblitz, S. Ramos, F. Haas, R. Geyer, R. Panknin, E. Rondio, Fabrice Gautheron, M. A. Faessler, V.Yu. Alexakhin, J. Polak, V.N. Kolosov, Christian Schill, N.S. Rossiyskaya, F. Kunne, R. Jahn, F. Tessarotto, C. Heß, C. Adolph, A. Korzenev, A. Grasso, J. M. Le Goff, D. Chaberny, V. Duic, E. M. Kabuß, O.P. Gavrichtchouk, A.A. Lednev, A. Nagaytsev, F. Balestra, A. Srnka, L. Sinha, T. Matsuda, G. D. Alexeev, F. Nerling, A.V. Efremov, W. Dünnweber, Yu.V. Mikhailov, R. Gushterski, Yu. Alexandrov, Yu. Kisselev, George I. Smirnov, S. Hedicke, Z.V. Kroumchtein, I.A. Savin, S. Grabmüller, I. Konorov, W.-D. Nowak, O.Yu. Denisov, A. Zvyagin, M. Ostrick, Bakur Parsamyan, C. Quintans, K. Zaremba, Alessandro Bressan, D. von Harrach, S. Gerassimov, G. Piragino, T. Guthörl, N. Horikawa, Sergey Donskov, L. Dhara, S. Ishimoto, Frank Klein, C. Braun, V.A. Polyakov, G. Sbrizzai, Ch. Höppner, A. Amoroso, S. Uhl, S.U. Chung, L. Schmitt, Oleg V. Ivanov, Maxence Vandenbroucke, B. Badelek, R. Birsa, Matthias Schott, N. du Fresne von Hohenesche, T. Schlüter, M. Giorgi, Michal Dziewiecki, E. Perevalova, S. Tessaro, E. Rocco, A. Richter, K. Klimaszewski, S. Das, R. Gazda, M. Chiosso, A.G. Olshevsky, Laura Silva, B. Ketzer, I. Uman, A. Morreale, Andres Cicuttin, A. Filin, A. Magnon, G. Reicherz, R. Joosten, V.D. Samoylenko, K. Kurek, A. Padee, L. G. Tkatchev, Yu.A. Khokhlov, D. Neyret, S. Paul, J. Pochodzalla, M. Stolarski, J.M. Friedrich, K. Bicker, R. Bertini, Andrea Ferrero, S. Dalla Torre, J. Bisplinghoff, S. Huber, G.V. Khaustov, S.S. Dasgupta, A. Mutter, Jean-Francois Rajotte, D.I. Ryabchikov, A.S. Nunes, Vladimir Nikolaenko, Miroslav Sulc, Aram Kotzinian, F. Hinterberger, P. Bordalo, D. Kang, R. Windmolders, H. Wollny, D. Panzieri, L. Lauser, O. Kouznetsov, E. Zemlyanichkina, W. Meyer, Maria Liz Crespo, J. Lichtenstadt, J. Marzec, Yu. Ivanshin, M.G. Alekseev, P. Jasinski, Franco Bradamante, M. V. Zavertyaev, Anne-Laure Martin, K. Schönning, Alexey Antonov, A. Bravar, P. Sznajder, J. ter Wolbeek, Johannes Bernhard, J. Nassalski, S. Sosio, S. Takekawa, M. Bettinelli, Michael Kramer, A. Guskov, K. Kondo, J. Barth, Y. Bedfer, E. Burtin, V.F. Konstantinov, A. Lehmann, C. Franco, J.H. Koivuniemi, C. Marchand, Gerhard K. Mallot, S. Goertz, V. Rapatsky, Sarben Sarkar, H. Fischer, P. Schiavon, K. Königsmann, A. Maggiora, B. Grube, N. dʼHose, N.V. Vlassov, Günter Baum, O.Yu. Shevchenko, S. Levorato, R. Garfagnini, M. Finger, Murray Moinester, François Herrmann, S. Platchkov, Lei Wang, M. Slunecka, M. Virius, W. Wiślicki, G.B. Pontecorvo, B. Gobbo, N. I. Zhuravlev, Federica Sozzi, S. Schopferer, T. Nagel, J. Pretz, R. Sulej, S. Procureur, T. Michigami, A. Mann, W. Eyrich, Nour Makke, J. Bieling, A. Sandacz, M. Quaresma, M.G. Sapozhnikov, K. Schmidt, D.V. Peshekhonov, Norihiro Doshita, A. N. Sissakian, G. Pesaro, I. Gnesi, P.D. Eversheim, S. Neubert, T. Iwata, M. Ziembicki, F. H. Heinsius, A. Austregesilo, C. Elia
Rok vydání: 2013
Předmět:
Zdroj: Physics Letters B. 718:922-930
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2012.11.056
Popis: We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with Q(2) > 1 (GeV/c)(2) including 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/c polarised muon beam scattering off a polarised (LiD)-Li-6 target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x(g) covering the range 0.04 < x(g) < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x(g). Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at average x(g) = 0.09 and a scale of mu(2) = 3 (GeV/c)(2).
Databáze: OpenAIRE
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