1. Leading order determination of the gluon polarisation from DIS events with high-pThadron pairs
- Author
-
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, and C. Elia
- Subjects
Physics ,Quantum chromodynamics ,Nuclear and High Energy Physics ,Particle physics ,Muon ,Proton ,010308 nuclear & particles physics ,Hadron ,Deep inelastic scattering ,01 natural sciences ,Gluon ,Nuclear physics ,0103 physical sciences ,COMPASS experiment ,High Energy Physics::Experiment ,Nuclear Experiment ,010306 general physics ,Nucleon - Abstract
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).
- Published
- 2013
- Full Text
- View/download PDF