0000000000275319

AUTHOR

Jinkui Zhao

showing 3 related works from this author

Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries

1998

We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\De…

QuarkPhysicsNuclear and High Energy PhysicsParticle physicsMuonValence (chemistry)SMCHadronFOS: Physical sciencesSMC; SIDIS; Polarized quark distributionsDeep inelastic scatteringSIDISHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)DeuteriumHigh Energy Physics::ExperimentPolarized quark distributionsNucleonParticle Physics - ExperimentPhysics Letters B
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Spin asymmetries for events with highpThadrons in DIS and an evaluation of the gluon polarization

2004

We present a measurement of the longitudinal spin cross section asymmetry for deep-inelastic muon-nucleon interactions with two high transverse momentum hadrons in the final state. Two methods of event classification are used to increase the contribution of the photon-gluon fusion process to above 30%. The most effective one, based on a neural network approach, provides the asymmetries A(p)lN(-->)lhhX=0.030+/-0.057(stat)+/-0.010(syst) and A(d)lN(-->)lhhX=0.070+/-0.076(stat)+/-0.010(syst). From these values we derive an averaged gluon polarization DeltaG/G=-0.20+/-0.28(stat)+/-0.10(syst) at an average fraction of nucleon momentum carried by gluons =0.07.

PhysicsNuclear and High Energy PhysicsParticle physicsMeson production010308 nuclear & particles physicsmedia_common.quotation_subjectHadronDeep inelastic scatteringPolarization (waves)01 natural sciencesAsymmetryGluonNuclear physics0103 physical sciencesTransverse momentumHigh Energy Physics::ExperimentAstrophysics::Earth and Planetary AstrophysicsNuclear Experiment010306 general physicsNucleonmedia_commonPhysical Review D
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The polarized double cell target of the SMC

1999

The polarized target of the Spin Muon Collaboration at CERN was used for deep inelastic muon scattering experiments during 1993-1996 with a polarized muon beam to investigate the spin structure of the nucleon. Most of the experiments were carried out with longitudinal target polarization and 190 GeV muons, and some were done with transverse polarization and 100 GeV muons. Protons as well as deuterons were polarized by dynamic nuclear polarization (DNP) in three kinds of solid materials - butanol, ammonia, and deuterated butanol - with maximum degrees of polarization of 94%, 91% and 60%, respectively. Considerable attention was paid to the accuracies of the NMR polarization measurements and …

PhysicsNuclear and High Energy PhysicsDISLarge Hadron ColliderMuonanalysisScatteringSMCPolarized targetSpin structurepolarized protons and deuteronsPolarization (waves)Deep inelastic scatteringNMRdynamic nuclear polarizationSMC; DIS; Polarized targetNuclear physicsDeuteriumPhysics::Accelerator PhysicsHigh Energy Physics::ExperimentDetectors and Experimental TechniquesNuclear ExperimentNucleonInstrumentation
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