Pagina principale > CERN Experiments > Fixed Target Experiments > COMPASS > COMPASS Conference Proceedings > Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering |
Article | |
Report number | arXiv:1007.4061 ; CERN-PH-EP-2010-023 ; CERN-PH-EP-2010-023 |
Title | Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering |
Author(s) |
Alekseev, M.G. (INFN, Turin) ; Alexakhin, V.Yu. (Dubna, JINR) ; Alexandrov, Yu. (Lebedev Inst.) ; Alexeev, G.D. (Dubna, JINR) ; Amoroso, A. (Turin U. ; INFN, Turin) ; Austregesilo, A. (CERN ; Munich, Tech. U.) ; Badelek, B. (Warsaw, Inst. Nucl. Studies) ; Balestra, F. (Turin U. ; INFN, Turin) ; Barth, J. (Bonn U.) ; Baum, G. (Bielefeld U.) ; Bedfer, Y. (IRFU, SPhN, Saclay) ; Bernhard, J. (Mainz U., Inst. Kernphys.) ; Bertini, R. (Turin U. ; INFN, Turin) ; Bettinelli, M. (Munich U.) ; Birsa, R. (INFN, Trieste) ; Bisplinghoff, J. (Bonn U., HISKP) ; Bordalo, P. (LIP, Lisbon) ; Bradamante, F. (Trieste U. ; INFN, Trieste) ; Bravar, A. (INFN, Trieste) ; Bressan, A. (Trieste U. ; INFN, Trieste) ; Brona, G. (CERN ; Warsaw, Inst. Nucl. Studies) ; Burtin, E. (IRFU, SPhN, Saclay) ; Bussa, M.P. (Turin U. ; INFN, Turin) ; Chaberny, D. (Mainz U., Inst. Kernphys.) ; Chiosso, M. (Turin U. ; INFN, Turin) ; Chung, S.U. (Munich, Tech. U.) ; Cicuttin, A. (ICTP, Trieste ; INFN, Trieste) ; Colantoni, M. (INFN, Turin) ; Crespo, M.L. (ICTP, Trieste ; INFN, Trieste) ; Dalla Torre, S. (INFN, Trieste) ; Das, S. (Matrivani Inst., Calcutta) ; Dasgupta, S.S. (Matrivani Inst., Calcutta) ; Denisov, O.Yu. (CERN ; INFN, Turin) ; Dhara, L. (Matrivani Inst., Calcutta) ; Diaz, V. (ICTP, Trieste ; INFN, Trieste) ; Donskov, S.V. (Serpukhov, IHEP) ; Doshita, N. (Ruhr U., Bochum ; Yamagata U.) ; Duic, V. (Trieste U. ; INFN, Trieste) ; Dunnweber, W. (Munich U.) ; Efremov, A. (Dubna, JINR) ; El Alaoui, A. (IRFU, SPhN, Saclay) ; Eversheim, P.D. (Bonn U., HISKP) ; Eyrich, W. (Erlangen - Nuremberg U.) ; Faessler, M. (Munich U.) ; Ferrero, A. (IRFU, SPhN, Saclay) ; Filin, A. (Serpukhov, IHEP) ; Finger, M. (Charles U.) ; Finger, M., Jr. (Dubna, JINR) ; Fischer, H. (Freiburg U.) ; Franco, C. (LIP, Lisbon) ; Friedrich, J.M. (Munich, Tech. U.) ; Garfagnini, R. (Turin U. ; INFN, Turin) ; Gautheron, F. (Ruhr U., Bochum) ; Gavrichtchouk, O.P. (Dubna, JINR) ; Gazda, R. (Warsaw, Inst. Nucl. Studies) ; Gerassimov, S. (Lebedev Inst. ; Munich, Tech. U.) ; Geyer, R. (Munich U.) ; Giorgi, M. (Trieste U. ; INFN, Trieste) ; Gnesi, I. (Turin U. ; INFN, Turin) ; Gobbo, B. (INFN, Trieste) ; Goertz, S. (Ruhr U., Bochum ; Bonn U.) ; Grabmuller, S. (Munich, Tech. U.) ; Grasso, A. (Turin U. ; INFN, Turin) ; Grube, B. (Munich, Tech. U.) ; Gushterski, R. (Dubna, JINR) ; Guskov, A. (Dubna, JINR) ; Haas, F. (Munich, Tech. U.) ; von Harrach, D. (Mainz U., Inst. Kernphys.) ; Hasegawa, T. (Miyazaki U.) ; Heinsius, F.H. (Freiburg U.) ; Herrmann, F. (Freiburg U.) ; Hess, C. (Ruhr U., Bochum) ; Hinterberger, F. (Bonn U., HISKP) ; Horikawa, N. (Nagoya U.) ; Hoppner, Ch. (Munich, Tech. U.) ; d'Hose, N. (IRFU, SPhN, Saclay) ; Ilgner, C. (CERN ; Munich U.) ; Ishimoto, S. (Nagoya U.) ; Ivanov, O. (Dubna, JINR) ; Ivanshin, Yu. (Dubna, JINR) ; Iwata, T. (Yamagata U.) ; Jahn, R. (Bonn U., HISKP) ; Jasinski, P. (Mainz U., Inst. Kernphys.) ; Jegou, G. (IRFU, SPhN, Saclay) ; Joosten, R. (Bonn U., HISKP) ; Kabuss, E. (Mainz U., Inst. Kernphys.) ; Kang, D. (Freiburg U.) ; Ketzer, B. (Munich, Tech. U.) ; Khaustov, G.V. (Serpukhov, IHEP) ; Khokhlov, Yu.A. (Serpukhov, IHEP) ; Kisselev, Yu. (Ruhr U., Bochum) ; Klein, F. (Bonn U.) ; Klimaszewski, K. (Warsaw, Inst. Nucl. Studies) ; Koblitz, S. (Mainz U., Inst. Kernphys.) ; Koivuniemi, J.H. (Ruhr U., Bochum) ; Kolosov, V.N. (Serpukhov, IHEP) ; Kondo, K. (Ruhr U., Bochum ; Yamagata U.) ; Konigsmann, K. (Freiburg U.) ; Konopka, R. (Munich, Tech. U.) ; Konorov, I. (Lebedev Inst. ; Munich, Tech. U.) ; Konstantinov, V.F. (Serpukhov, IHEP) ; Korzenev, A. (IRFU, SPhN, Saclay) ; Kotzinian, A.M. (Turin U. ; INFN, Turin) ; Kouznetsov, O. (Dubna, JINR ; IRFU, SPhN, Saclay) ; Kowalik, K. (Warsaw, Inst. Nucl. Studies ; IRFU, SPhN, Saclay) ; Kramer, M. (Munich, Tech. U.) ; Kral, A. (Prague, Tech. U.) ; Kroumchtein, Z.V. (Dubna, JINR) ; Kuhn, R. (Munich, Tech. U.) ; Kunne, F. (IRFU, SPhN, Saclay) ; Kurek, K. (Warsaw, Inst. Nucl. Studies) ; Lauser, L. (Freiburg U.) ; Le Goff, J.M. (IRFU, SPhN, Saclay) ; Lednev, A.A. (Serpukhov, IHEP) ; Lehmann, A. (Erlangen - Nuremberg U.) ; Levorato, S. (Trieste U. ; INFN, Trieste) ; Lichtenstadt, J. (Tel Aviv U.) ; Liska, T. (Prague, Tech. U.) ; Maggiora, A. (INFN, Turin) ; Maggiora, M. (Turin U. ; INFN, Turin) ; Magnon, A. (IRFU, SPhN, Saclay) ; Makke, N. (IRFU, SPhN, Saclay) ; Mallot, G.K. (CERN) ; Mann, A. (Munich, Tech. U.) ; Marchand, C. (IRFU, SPhN, Saclay) ; Martin, A. (Trieste U. ; INFN, Trieste) ; Marzec, J. (Warsaw U. of Tech.) ; Massmann, F. (Bonn U., HISKP) ; Matsuda, T. (Miyazaki U.) ; Meyer, W. (Ruhr U., Bochum) ; Michigami, T. (Yamagata U.) ; Mikhailov, Yu.V. (Serpukhov, IHEP) ; Moinester, M.A. (Tel Aviv U.) ; Mutter, A. (Freiburg U. ; Mainz U., Inst. Kernphys.) ; Nagaytsev, A. (Dubna, JINR) ; Nagel, T. (Munich, Tech. U.) ; Nassalski, J. (Warsaw, Inst. Nucl. Studies) ; Negrini, T. (Bonn U., HISKP) ; Nerling, F. (Freiburg U.) ; Neubert, S. (Munich, Tech. U.) ; Neyret, D. (IRFU, SPhN, Saclay) ; Nikolaenko, V.I. (Serpukhov, IHEP) ; Nunes, A.S. (LIP, Lisbon) ; Olshevsky, A.G. (Dubna, JINR) ; Ostrick, M. (Mainz U., Inst. Kernphys.) ; Padee, A. (Warsaw U. of Tech.) ; Panknin, R. (Bonn U.) ; Panzieri, D. (Turin U., Alessandria ; INFN, Turin) ; Parsamyan, B. (Turin U. ; INFN, Turin) ; Paul, S. (Munich, Tech. U.) ; Pawlukiewicz-Kaminska, B. (Warsaw, Inst. Nucl. Studies) ; Perevalova, E. (Dubna, JINR) ; Pesaro, G. (Trieste U. ; INFN, Trieste) ; Peshekhonov, D.V. (Dubna, JINR) ; Piragino, G. (Turin U. ; INFN, Turin) ; Platchkov, S. (IRFU, SPhN, Saclay) ; Pochodzalla, J. (Mainz U., Inst. Kernphys.) ; Polak, J. (Liberec Tech. U. ; Trieste U. ; INFN, Trieste) ; Polyakov, V.A. (Serpukhov, IHEP) ; Pontecorvo, G. (Dubna, JINR) ; Pretz, J. (Bonn U.) ; Quintans, C. (LIP, Lisbon) ; Rajotte, J.F. (Munich U.) ; Ramos, S. (LIP, Lisbon) ; Rapatsky, V. (Dubna, JINR) ; Reicherz, G. (Ruhr U., Bochum) ; Richter, A. (Erlangen - Nuremberg U.) ; Robinet, F. (IRFU, SPhN, Saclay) ; Rocco, E. (Turin U. ; INFN, Turin) ; Rondio, E. (Warsaw, Inst. Nucl. Studies) ; Ryabchikov, D.I. (Serpukhov, IHEP) ; Samoylenko, V.D. (Serpukhov, IHEP) ; Sandacz, A. (Warsaw, Inst. Nucl. Studies) ; Santos, H. (LIP, Lisbon) ; Sapozhnikov, M.G. (Dubna, JINR) ; Sarkar, S. (Matrivani Inst., Calcutta) ; Savin, I.A. (Dubna, JINR) ; Sbrizzai, G. (Trieste U. ; INFN, Trieste) ; Schiavon, P. (Trieste U. ; INFN, Trieste) ; Schill, C. (Freiburg U.) ; Schluter, T. (Munich U.) ; Schmitt, L. (Munich, Tech. U.) ; Schopferer, S. (Freiburg U.) ; Schroder, W. (Erlangen - Nuremberg U.) ; Shevchenko, O.Yu. (Dubna, JINR) ; Siebert, H.W. (Mainz U., Inst. Kernphys.) ; Silva, L. (LIP, Lisbon) ; Sinha, L. (Matrivani Inst., Calcutta) ; Sissakian, A.N. (Dubna, JINR) ; Slunecka, M. (Dubna, JINR) ; Smirnov, G.I. (Dubna, JINR) ; Sosio, S. (Turin U. ; INFN, Turin) ; Sozzi, F. (Trieste U. ; INFN, Trieste) ; Srnka, A. (Inst. Sci. Instruments, Brno) ; Stolarski, M. (CERN) ; Sulc, M. (Liberec Tech. U.) ; Sulej, R. (Warsaw U. of Tech.) ; Takekawa, S. (Trieste U. ; INFN, Trieste) ; Tessaro, S. (INFN, Trieste) ; Tessarotto, F. (INFN, Trieste) ; Teufel, A. (Erlangen - Nuremberg U.) ; Tkatchev, L.G. (Dubna, JINR) ; Uhl, S. (Munich, Tech. U.) ; Uman, I. (Munich U.) ; Virius, M. (Prague, Tech. U.) ; Vlassov, N.V. (Dubna, JINR) ; Vossen, A. (Freiburg U.) ; Weitzel, Q. (Munich, Tech. U.) ; Windmolders, R. (Bonn U.) ; Wislicki, W. (Warsaw, Inst. Nucl. Studies) ; Wollny, H. (Freiburg U.) ; Zaremba, K. (Warsaw U. of Tech.) ; Zavertyaev, M. (Lebedev Inst.) ; Zemlyanichkina, E. (Dubna, JINR) ; Ziembicki, M. (Warsaw U. of Tech.) ; Zhao, J. (Mainz U., Inst. Kernphys. ; INFN, Trieste) ; Zhuravlev, N. (Dubna, JINR) ; Zvyagin, A. (Munich U.) |
Publication | 2010 |
Imprint | 21 Jul 2010 |
Number of pages | 13 |
Note | Comments: 13 pages, 5 figures 13 pages, 5 figures |
In: | Phys. Lett. B 693 (2010) 227-235 |
DOI | 10.1016/j.physletb.2010.08.034 |
Subject category | Particle Physics - Experiment ; Particle Physics - Experiment |
Accelerator/Facility, Experiment | CERN SPS ; COMPASS NA58 |
Free keywords | COMPASS ; semi-inclusive deep inelastic scattering ; spin ; structure function ; parton distribution functions |
Abstract | Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a longitudinally polarised NH_3 target, cover a range of the Bjorken variable x between 0.004 and 0.7. A leading order evaluation of the helicity distributions for the three lightest quarks and antiquark flavours derived from these asymmetries and from our previous deuteron data is presented. The resulting values of the sea quark distributions are small and do not show any sizable dependence on x in the range of the measurements. No significant difference is observed between the strange and antistrange helicity distributions, both compatible with zero. The integrated value of the flavour asymmetry of the helicity distribution of the light-quark sea, \Delta u-bar - \Delta d-bar, is found to be slightly positive, about 1.5 standard deviations away from zero. |
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