Leading order determination of the gluon polarisation from DIS events with high-p(T) hadron pairs

C. Adolph (1) , M.G. Alekseev , V.Yu. Alexakhin , Yu. Alexandrov , G.D. Alexeev , A. Amoroso , A.A. Antonov , A. Austregesilo , B. Badełek , F. Balestra (2) , J. Barth , G. Baum , Y. Bedfer (3) , J. Bernhard , R. Bertini , M. Bettinelli (4) , K. Bicker , J. Bieling , R. Birsa , J. Bisplinghoff , P. Bordalo , F. Bradamante , C. Braun , A. Bravar , A. Bressan (5) , E. Burtin (3) , D. Chaberny , M. Chiosso , S.U. Chung (6) , A. Cicuttin (7) , M.L. Crespo , S. Dalla Torre , S. Das (8) , S.S. Dasgupta (9) , O.Yu. Denisov , L. Dhara , S.V. Donskov , N. Doshita , V. Duic , W. Dünnweber , M. Dziewiecki , A. Efremov , C. Elia (10) , P.D. Eversheim , W. Eyrich , M. Faessler , A. Ferrero (3) , A. Filin , M. Finger , H. Fischer (11) , C. Franco (12) , N. Du Fresne von Hohenesche , J.M. Friedrich , R. Garfagnini , F. Gautheron , O.P. Gavrichtchouk , R. Gazda , S. Gerassimov , R. Geyer , M. Giorgi , I. Gnesi , B. Gobbo , S. Goertz , S. Grabmüller , A. Grasso (13) , B. Grube , R. Gushterski , A. Guskov , T. Guthörl , F. Haas , D. von Harrach , S. Hedicke , F.H. Heinsius , F. Herrmann (14) , C. Hess , F. Hinterberger , N. Horikawa , Ch. Höppner , N. Dʼhose (3) , S. Huber (15) , S. Ishimoto , O. Ivanov , Yu. Ivanshin , T. Iwata (16) , R. Jahn , P. Jasinski , R. Joosten (17) , E. Kabuss , D. Kang , B. Ketzer , G.V. Khaustov , Yu.A. Khokhlov , Yu. Kisselev , F. Klein (18) , K. Klimaszewski , S. Koblitz , J.H. Koivuniemi , V.N. Kolosov , K. Kondo , K. Königsmann , I. Konorov , V.F. Konstantinov , A. Korzenev (3) , A.M. Kotzinian , O. Kouznetsov , M. Krämer (19) , Z.V. Kroumchtein , F. Kunne (3) , K. Kurek , L. Lauser , J.-M. Le Goff (20, 21) , A.A. Lednev , A. Lehmann (22, 23, 24) , S. Levorato , J. Lichtenstadt , A. Maggiora , A. Magnon (3) , N. Makke (3) , G.K. Mallot , A. Mann (25) , C. Marchand (3) , A. Martin (26) , J. Marzec , T. Matsuda , W. Meyer , T. Michigami , Yu.V. Mikhailov , M.A. Moinester , A. Morreale (3) , A. Mutter , A. Nagaytsev , T. Nagel , J.P. Nassalski , F. Nerling , S. Neubert , D. Neyret (3) , V.I. Nikolaenko , W.D. Nowak , A.S. Nunes , A.G. Olshevsky , M. Ostrick , A. Padee , R. Panknin , D. Panzieri , B. Parsamyan , S. Paul (27) , E. Perevalova , G. Pesaro , D.V. Peshekhonov , G. Piragino , S. Platchkov (3) , J. Pochodzalla , J. Polak (28) , V.A. Polyakov , G. Pontecorvo , J. Pretz , S.L. Procureur , M. Quaresma , C. Quintans , J.-F. Rajotte , S. Ramos (29) , V. Rapatsky , G. Reicherz , A. Richter (30) , E. Rocco , E. Rondio , N.S. Rossiyskaya , D.I. Ryabchikov , V.D. Samoylenko , A. Sandacz , M.G. Sapozhnikov , S. Sarkar (31) , I.A. Savin , G. Sbrizzai , P. Schiavon , C. Schill , T. Schlüter , K. Schmidt , L. Schmitt (32) , K. Schönning , S. Schopferer , M. Schott (33) , O.Yu. Shevchenko , L. Silva , L. Sinha , A.N. Sissakian , M. Slunecka , George Smirnov (34) , S. Sosio , F. Sozzi , A. Srnka , M. Stolarski , M. Sulc , R. Sulej , P. Sznajder , S. Takekawa , J. ter Wolbeek , S. Tessaro , F. Tessarotto , L.G. Tkatchev , S. Uhl , I. Uman , M. Vandenbroucke (3) , M. Virius , N.V. Vlassov , L. Wang (35) , R. Windmolders , W. Wiślicki , H. Wollny (3) , K. Zaremba , M. Zavertyaev , E. Zemlyanichkina , M. Ziembicki , N. Zhuravlev , A. Zvyagin

1 Physikalisches Institut [Erlangen]
2 LPCS - Laboratoire de Physique des Composants à Semiconducteurs
3 DPHN - Département de Physique Nucléaire (ex SPhN)
4 UNIVR - Università degli studi di Verona = University of Verona
5 Department of Mathematics [Philadelphia]
6 NTU - National Taiwan University [Taiwan]
7 ICTP - Abdus Salam International Centre for Theoretical Physics [Trieste]
8 LIF - Laboratoire d'informatique Fondamentale de Marseille
9 Department of Zoology
10 UA - Université Antonine
11 IMK - Institute for Meteorology and Climate Research
12 L2C2 - Institut des Sciences cognitives Marc Jeannerod - Laboratoire sur le langage, le cerveau et la cognition
13 Archeobotanica e Paleoecologia
14 Physikalisches Institut [Freiburg]
15 Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck]
16 Department of Environmental and Materials Engineering
17 ICIS - Institute for Computing and Information Sciences [Nijmegen]
18 Laboratory of Molecular Immunology
19 University of Manchester [Manchester]
20 UNICAEN - Université de Caen Normandie
21 NU - Normandie Université
22 Department of Otolaryngology - Head and Neck Surgery
23 Centre for Research on Brain, Language and Music
24 BRAMS - International Laboratory for Brain, Music and Sound Research
25 Princeton University
26 aucun
27 AGM - UMR 8088 - Analyse, Géométrie et Modélisation
28 Franco-czech Laboratory for clinical research on obesity
29 ICSN - Institut de Chimie des Substances Naturelles
30 IUP - Institute of Environmental Physics [Bremen]
31 CAM - University of Cambridge [UK]
32 National School of Mountain Sports/National Ski-Nordic Centre
33 IBMM - Institut des Biomolécules Max Mousseron [Pôle Chimie Balard]
34 DMA - Departamento de Matemática e Aplicações
35 MOTIVATE - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales

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).

Domaines: Physique [physics]; Physique Nucléaire Expérimentale [nucl-ex]

C. Adolph, M.G. Alekseev, V.Yu. Alexakhin, Yu. Alexandrov, G.D. Alexeev, et al.. Leading order determination of the gluon polarisation from DIS events with high-p(T) hadron pairs. Physics Letters B, 2013, 718 (3), pp.922. ⟨10.1016/j.physletb.2012.11.056⟩. ⟨hal-01128794⟩