The gluon polarization in the nucleon was measured using open charm production by scattering 160 GeV/c polarized muons off longitudinally polarized protons or deuterons. The data were taken by the COMPASS Collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of D-0 mesons are investigated. Longitudinal spin asymmetries of the D meson production cross sections are extracted in bins of D-0 transverse momentum and energy. At leading order QCD accuracy, the average gluon polarization is determined as Delta g/g (LO) = -0.06 +/- 0: 21(stat.) +/- 0. 08(syst.) at the scale mu(2) approximate to 13 (GeV/c)(2) and an average gluon momentum fraction x approximate to 0.11. The average gluon polarization is also obtained at next-to-leading order QCD accuracy as Delta g/g NLO = -0.13 +/- 0.15(stat.).+/- 0.15(syst.) at the scale mu(2) approximate to 13 (GeV/c)(2) and x approximate to 0.20.

Leading and next-to-leading order gluon polarization in the nucleon and longitudinal double spin asymmetries from open charm muoproduction

AMOROSO, Antonio;BALESTRA, Ferruccio;BERTINI, Raimondo Pietro;CHIOSSO, Michela;GARFAGNINI, Raffaello;GNESI, IVAN;GRASSO, Antonino;PIRAGINO, Guido;SOSIO, Stefano;
2013-01-01

Abstract

The gluon polarization in the nucleon was measured using open charm production by scattering 160 GeV/c polarized muons off longitudinally polarized protons or deuterons. The data were taken by the COMPASS Collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of D-0 mesons are investigated. Longitudinal spin asymmetries of the D meson production cross sections are extracted in bins of D-0 transverse momentum and energy. At leading order QCD accuracy, the average gluon polarization is determined as Delta g/g (LO) = -0.06 +/- 0: 21(stat.) +/- 0. 08(syst.) at the scale mu(2) approximate to 13 (GeV/c)(2) and an average gluon momentum fraction x approximate to 0.11. The average gluon polarization is also obtained at next-to-leading order QCD accuracy as Delta g/g NLO = -0.13 +/- 0.15(stat.).+/- 0.15(syst.) at the scale mu(2) approximate to 13 (GeV/c)(2) and x approximate to 0.20.
2013
87
052018-1
052018-22
DEPENDENT STRUCTURE-FUNCTION; MONTE-CARLO GENERATOR; STRUCTURE-FUNCTION G(1)(D)
C. Adolph;M. G. Alekseev;V. Yu. Alexakhin;Yu. Alexandrov;G. D. Alexeev;A. Amoroso;A. A. Antonov;A. Austregesilo;B. Badełek;F. Balestra;J. Barth;G. Baum;Y. Bedfer;A. Berlin;J. Bernhard;R. Bertini;M. Bettinelli;K. Bicker;J. Bieling;R. Birsa;J. Bisplinghoff;P. Bordalo;F. Bradamante;C. Braun;A. Bravar;A. Bressan;M. Büchele;E. Burtin;L. Capozza;M. Chiosso;S. U. Chung;A. Cicuttin;M. L. Crespo;S. Dalla Torre;S. Das;S. S. Dasgupta;S. Dasgupta;O. Yu. Denisov;L. Dhara;S. V. Donskov;N. Doshita;V. Duic;W. Dünnweber;M. Dziewiecki;A. Efremov;C. Elia;P. D. Eversheim;W. Eyrich;M. Faessler;A. Ferrero;A. Filin;M. Finger;M. Finger;H. Fischer;C. Franco;N. du Fresne von Hohenesche;J. M. Friedrich;V. Frolov;R. Garfagnini;F. Gautheron;O. P. Gavrichtchouk;S. Gerassimov;R. Geyer;M. Giorgi;I. Gnesi;B. Gobbo;S. Goertz;S. Grabmüller;A. Grasso;B. Grube;R. Gushterski;A. Guskov;T. Guthörl;F. Haas;D. von Harrach;F. H. Heinsius;F. Herrmann;C. Heß;F. Hinterberger;N. Horikawa;Ch. Höppner;N. d’Hose;S. Huber;S. Ishimoto;O. Ivanov;Yu. Ivanshin;T. Iwata;R. Jahn;V. Jary;P. Jasinski;R. Joosten;E. Kabuß;D. Kang;B. Ketzer;G. V. Khaustov;Yu. A. Khokhlov;Yu. Kisselev;F. Klein;K. Klimaszewski;S. Koblitz;J. H. Koivuniemi;V. N. Kolosov;K. Kondo;K. Königsmann;I. Konorov;V. F. Konstantinov;A. Korzenev;A. M. Kotzinian;O. Kouznetsov;M. Krämer;Z. V. Kroumchtein;F. Kunne;K. Kurek;L. Lauser;A. A. Lednev;A. Lehmann;S. Levorato;J. Lichtenstadt;T. Liska;A. Maggiora;A. Magnon;N. Makke;G. K. Mallot;A. Mann;C. Marchand;A. Martin;J. Marzec;T. Matsuda;G. Meshcheryakov;W. Meyer;T. Michigami;Yu. V. Mikhailov;A. Morreale;A. Mutter;A. Nagaytsev;T. Nagel;F. Nerling;S. Neubert;D. Neyret;V. I. Nikolaenko;W.-D. Nowak;A. S. Nunes;A. G. Olshevsky;M. Ostrick;A. Padee;R. Panknin;D. Panzieri;B. Parsamyan;S. Paul;E. Perevalova;G. Pesaro;D. V. Peshekhonov;G. Piragino;S. Platchkov;J. Pochodzalla;J. Polak;V. A. Polyakov;J. Pretz;M. Quaresma;C. Quintans;J.-F. Rajotte;S. Ramos;V. Rapatsky;G. Reicherz;E. Rocco;E. Rondio;N. S. Rossiyskaya;D. I. Ryabchikov;V. D. Samoylenko;A. Sandacz;M. G. Sapozhnikov;S. Sarkar;I. A. Savin;G. Sbrizzai;P. Schiavon;C. Schill;T. Schlüter;A. Schmidt;K. Schmidt;L. Schmitt;H. Schmïden;K. Schönning;S. Schopferer;M. Schott;O. Yu. Shevchenko;L. Silva;L. Sinha;A. N. Sissakian;M. Slunecka;G. I. Smirnov;S. Sosio;F. Sozzi;A. Srnka;L. Steiger;M. Stolarski;M. Sulc;R. Sulej;H. Suzuki;P. Sznajder;S. Takekawa;J. Ter Wolbeek;S. Tessaro;F. Tessarotto;L. G. Tkatchev;S. Uhl;I. Uman;M. Vandenbroucke;M. Virius;N. V. Vlassov;L. Wang;T. Weisrock;M. Wilfert;R. Windmolders;W. Wiślicki;H. Wollny;K. Zaremba;M. Zavertyaev;E. Zemlyanichkina;M. Ziembicki;N. Zhuravlev;A. Zvyagin
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/148765
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