We present a determination of the gluon polarization ΔG/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q2<1 2(GeV/c), with 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 polarized muon beam scattered on a polarized 6LiD target. The helicity asymmetry for the selected events is 〈A∥/D〉=0.002±0.019(stat)±0.003(syst). From this value, we obtain in a leading-order QCD analysis ΔG/G=0.024±0.089(stat)±0.057(syst) at xg=0.095 and μ2≃3 2(GeV/c).

Gluon polarization in the nucleon from quasi-real photoproduction of high-p(T) hadron pairs

AMOROSO, Antonio;BALESTRA, Ferruccio;BERTINI, Raimondo Pietro;BUSSA, Maria Pia;COSTA, Sergio;FERRERO, Andrea;FERRERO, Livio;FROLOV, VLADIMIR;GARFAGNINI, Raffaello;GRASSO, Antonino;KOTZINIAN, Aram;MAGGIORA, MARCO;PANZIERI, Daniele;PIRAGINO, Guido;
2006

Abstract

We present a determination of the gluon polarization ΔG/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q2<1 2(GeV/c), with 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 polarized muon beam scattered on a polarized 6LiD target. The helicity asymmetry for the selected events is 〈A∥/D〉=0.002±0.019(stat)±0.003(syst). From this value, we obtain in a leading-order QCD analysis ΔG/G=0.024±0.089(stat)±0.057(syst) at xg=0.095 and μ2≃3 2(GeV/c).
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E.S. AGEEV; V.YU. ALEXAKHIN; YU. ALEXANDROV; G.D. ALEXEEV; A. AMOROSO; B. BADELEK; F. BALESTRA; J. BALL; G. BAUM; Y. BEDFER; P. BERGLUND; R. BERTINI; R. BIRSA; J. BISPLINGHOFF; F. BRADAMANTE; A. BRAVAR; A. BRESSAN; G. BRONA; E. BURTIN; M.P. BUSSA; V.N. BYTCHKOV; L. CERINI; A. CHAPIRO; A. CICUTTIN; M. COLANTONI; A.A. COLAVITA; S. COSTA; M.L. CRESPO; S. DALLA TORRE; S.S. DASGUPTA; N. DEDEK; R. DE MASI;O. DENISOV; L. DHARA; V. DIAZ; A.M. DINKELBACH; A.V. DOLGOPOLOV; S.V. DONSKOV; V.A. DOROFEEV; V. DUIC; P.D. EVERSHEIM; W. EYRICH; M. FABRO; M. FAESSLER; V. FALALEEV; P. FAULAND; A. FERRERO; L. FERRERO; M. FINGER; M. FINGER; JR; H. FISCHER; J. FRANZ; J.M. FRIEDRICH; V. FROLOV; R. GARFAGNINI; F. GAUTHERON; O.P. GAVRICHTCHOUK; R. GEYER; M. GIORGI; B. GOBBO; A.M. GORIN; O.A. GRAJEK; A. GRASSO; B. GRUBE; J. HANNAPPEL; D. VON HARRACH; T. HASEGAWA; S. HEDICKE; R. HERMANN; F. HINTERBERGER; M. VON HODENBERG; N. HORIKAWA; N. D''HOSE; R.B. IJADUOLA; C. ILGNER; A.I. IOUKAEV; S. ISHIMOTO; O. IVANOV; T. IWATA; R. JAHN; A. JANATA; R. JOOSTEN; N.I. JOURAVLEV; V. KALINNIKOV; D. KANG; F. KARSTENS; W. KASTAUN; B. KETZER; G.V. KHAUSTOV; YU.A. KHOKHLOV; N.V. KHOMUTOV; F. KLEIN; S. KOBLITZ; V.N. KOLOSOV; E.V. KOMISSAROV; A.K. KONOPLYANNIKOV; V.F. KONSTANTINOV; A.S. KORENTCHENKO; AM KOTZINIAN; N.A. KOUTCHINSKI; K. KOWALIK; N.P. KRAVCHUK; G.V. KRIVOKHIZHIN; Z.V. KROUMCHTEIN; R. KUHN; F. KUNNE; K. KUREK; M.E. LADYGIN; J.M. LE GOFF; J. LICHTENSTADT; T. LISKA; I. LUDWIG; A. MAGGIORA; M. MAGGIORA; A. MAGNON; G.K. MALLOT; I.V. MANUILOV; C. MARCHAND; J. MARRONCLE; A. MARTIN; J. MARZEC; T. MATSUDA; A.N. MAXIMOV; K.S. MEDVED; W. MEYER; YU.V. MIKHAILOV; M.A. MOINESTER; J. NASSALSKI; S. NELIBA; D.P. NEYRET; V.I. NIKOLAENKO; A.A. NOZDRIN; V.F. OBRAZTSOV; A.G. OLSHEVSKY; M. OSTRICK; A. PADEE; P. PAGANO; S. PANEBIANCO;D. PANZIERI; S. PAUL; D.V. PESHEKHONOV; V.D. PESHEKHONOV; G. PIRAGINO; S. PLATCHKOV; K. PLATZER; J. POCHODZALLA; V.A. POLYAKOV; A.A. POPOV; S. PROCUREUR; C. QUINTANS; P.C. REBOURGEARD; G. REICHERZ; J. REYMANN; E. RONDIO; A.M. ROZHDESTVENSKY; A.B. SADOVSKI; E. SALLER; V.D. SAMOYLENKO; A. SANDACZ; M. SANS; M.G. SAPOZHNIKOV; I.A. SAVIN; P. SCHIAVON; C. SCHILL; T. SCHMIDT; H. SCHMITT; O.YU. SHEVCHENKO; A.A. SHISHKIN; H.-W. SIEBERT; L. SINHA; A.N. SISSAKIAN; A. SKACHKOVA; M. SLUNECKA; G.I. SMIRNOV; F. SOZZI; A. SRNKA; F. STINZING; M. STOLARSKI; V.P. SUGONYAEV; M. SULC; R. SULEJ; N. TAKABAYASHI; V.V. TCHALISHEV; F. TESSAROTTO; A. TEUFEL; D. THERS; L.G. TKATCHEV; T. TOEDA; V.I. TRETYAK; S. TROUSOV; M. VARANDA; M. VIRIUS; N.V. VLASSOV; M. WAGNER; R. WEBB; E. WEISE; Q. WEITZEL; U. WIEDNER; M. WIESMANN; R. WINDMOLDERS; S. WIRTH; W. WISLICKI; A.M. ZANETTI; K. ZAREMBA; J. ZHAO; R. ZIEGLER; A. ZVYAGIN
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/103644
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