0000000000846509

AUTHOR

G. J. Kumbartzki

showing 3 related works from this author

Backward electroproduction ofπ0mesons on protons in the region of nucleon resonances at four momentum transfer squaredQ2=1.0GeV2

2004

Exclusive electroproduction of pi{sup 0} mesons on protons in the backward hemisphere has been studied at Q2 = 1.0 GeV2 by detecting protons in the forward direction in coincidence with scattered electrons from the 4 GeV electron beam in Jefferson Lab's Hall A. The data span the range of the total (gamma*p) center-of-mass energy W from the pion production threshold to W = 2.0 GeV. The differential cross sections sigma{sub T} + epsilon sigma{sub L}, sigma{sub TL}, and sigma{sub TT} were separated from the azimuthal distribution and are presented together with the MAID and SAID parameterizations.

PhysicsNuclear and High Energy PhysicsParticle physicsMeson010308 nuclear & particles physicsNuclear TheoryHadronMomentum transferSigma01 natural sciencesNuclear physicsBaryonPion0103 physical sciencesHigh Energy Physics::ExperimentNuclear Experiment010306 general physicsNucleonLeptonPhysical Review C
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Polarization transfer in the 4HeH reaction

2001

Abstract Polarization transfer in the 4He ( e → ,e′ p → ) 3 H reaction at a Q2 of 0.4 (GeV/c)2 was measured at the Mainz Microtron MAMI. The ratio of the transverse to the longitudinal polarization components of the ejected protons was compared with the same ratio for elastic ep scattering. The results are consistent with a recent fully relativistic calculation which includes a predicted medium modification of the proton form factor based on a quark–meson coupling model.

PhysicsNuclear and High Energy PhysicsProtonScatteringNuclear Theorychemistry.chemical_elementPolarization (waves)Nuclear physicsTransverse planechemistryPhysics::Accelerator PhysicsNuclear ExperimentMicrotronHeliumPhysics Letters B
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Virtual Compton Scattering and Neutral Pion Electroproduction in the Resonance Region up to the Deep Inelastic Region at Backward Angles

2009

We have made the first measurements of the virtual Compton scattering (VCS) process via the H$(e,e'p)\gamma$ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the $W$-dependence at fixed $Q^2=1$ GeV$^2$, and for the $Q^2$-dependence at fixed $W$ near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed $Q^2$-dependence is smooth. The measured ratio of H$(e,e'p)\gamma$ to H$(e,e'p)\pi^0$ cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to Real Compton Scattering (RCS) at high energy and large angles, our VCS data…

Elastic scatteringPhysicsNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsScatteringCompton scatteringResonanceFOS: Physical sciencesInelastic scattering[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]Deep inelastic scattering01 natural sciencesHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)Pion0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear Experiment (nucl-ex)010306 general physicsNucleonNuclear Experiment
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