0000000000991587

AUTHOR

Marc Wagner

showing 3 related works from this author

A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

2007

New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations.

QuarkdeuteronNuclear and High Energy PhysicsParticle physicsPhysics::Instrumentation and DetectorsSivers asymmetryHadrontransversity and Sivers functionFOS: Physical sciencesCOMPASS01 natural sciencesHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)nucleon structure; transverse spin and transverse momentum; transversity and Sivers functions; deuteron; COMPASS experimentCompass0103 physical sciencesCOMPASS experimentCollins010306 general physicsNuclear ExperimentCOMPASS experimenttransversityPhysicsLarge Hadron ColliderMuonSpectrometer010308 nuclear & particles physicsScatteringtransversity and Sivers functionsnucleon structureHigh Energy Physics::Experimenttransverse spin and transverse momentumasymmetryParticle Physics - Experimenttransverse single-spin asymmetry
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Measurement of the Spin Structure of the Deuteron in the DIS Region

2005

We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.

Nuclear and High Energy PhysicsParticle physicsmedia_common.quotation_subjectFOS: Physical sciencesSpin structure01 natural sciencesAsymmetryCOMPASSHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)deep inelastic scatteringstructure function0103 physical sciencesCOMPASS experiment010306 general physicsNuclear Experimentmedia_commonSpin-½PhysicsLarge Hadron ColliderMuon010308 nuclear & particles physicsDeep inelastic scatteringstructure function; COMPASS; DEEP INELASTIC-SCATTERINGstructure functionsDEEP INELASTIC-SCATTERINGHigh Energy Physics::ExperimentParticle Physics - ExperimentBeam (structure)
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Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

2006

Abstract We present a determination of the gluon polarization Δ G / G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q 2 1 ( GeV / c ) 2 , 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 6 LiD 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 Δ G / G = 0.024 ± 0.089 ( stat ) ± 0.057 ( syst ) at x g = 0.095 and μ 2 ≃ 3 ( GeV / c ) 2 .

Quantum chromodynamicsPhysicsNuclear and High Energy PhysicsParticle physicsMuon010308 nuclear & particles physicsHadronDeep inelastic scattering01 natural sciencesHelicityGluonNuclear physics0103 physical sciencesCOMPASS experimentHigh Energy Physics::ExperimentNuclear Experiment010306 general physicsNucleonPhysics Letters B
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