0000000000472112

AUTHOR

E. Steffens

showing 3 related works from this author

Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on a longitudinally polarized deuterium target

2010

Azimuthal asymmetries in exclusive electroproduction of a real photon from a longitudinally polarized deuterium target are measured with respect to target polarization alone and with respect to target polarization combined with beam helicity and/or beam charge. The asymmetries appear in the distribution of the real photons in the azimuthal angle $\phi$ around the virtual photon direction, relative to the lepton scattering plane. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe-Heitler process. The results for the beam-charge and beam-helicity asymmetries from a tensor polarized deuterium target with vanishing vector polarization ar…

Nuclear and High Energy Physics/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyEVOLUTION KERNELS010308 nuclear & particles physicsGENERALIZED PARTON DISTRIBUTIONS; IMPACT PARAMETER SPACE; ELECTRON STORAGE-RING; EVOLUTION KERNELS; HERA; SPIN; NUCLEON; QCDHERAIMPACT PARAMETER SPACEFOS: Physical sciencesQCD01 natural sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)ELECTRON STORAGE-RINGSPINGENERALIZED PARTON DISTRIBUTIONS0103 physical sciencesddc:530High Energy Physics::ExperimentSDG 7 - Affordable and Clean EnergyNUCLEON010306 general physics
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Nuclear-mass dependence of azimuthal beam-helicity and beam-charge asymmetries in deeply virtual Compton scattering

2009

The nuclear-mass dependence of azimuthal cross section asymmetries with respect to charge and longitudinal polarization of the lepton beam is studiedfor hard exclusive electroproduction of real photons. The observed beam-charge and beam-helicity asymmetries are attributed to the interference between the Bethe-Heitler and deeply virtual Compton scattering processes. For various nuclei, the asymmetries are extracted for both coherent and incoherent-enriched regions, which involve different (combinations of) generalized parton distributions. For both regions, the asymmetries are compared to those for a free proton, and no nuclear-mass dependence is found.

Nuclear and High Energy PhysicsParticle physicsPhotonNuclear TheoryHERAFOS: Physical sciencesIMPACT PARAMETER SPACEPartonGENERALIZED PARTON DISTRIBUTIONS; IMPACT PARAMETER SPACE; SPIN; HERA01 natural sciences7. Clean energyHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)GENERALIZED PARTON DISTRIBUTIONS0103 physical sciencesddc:530Nuclear Experiment010306 general physicsPhysicsElastic scattering010308 nuclear & particles physicsScatteringCompton scatteringHERASPINPhysics::Accelerator PhysicsHigh Energy Physics::ExperimentNucleonBeam (structure)
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First experiments with the heidelberg test storage ring TSR

1989

Abstract The Heidelberg heavy ion test storage ring TSR started operation in May 1988. The lifetimes of the ion beams observed in the first experiments can be explained by interactions with the residual gas. Multiple Coulomb scattering, single Coulomb scattering, electron capture and electron stripping are the relevant processes. Electron cooling of ions as heavy as O 8+ has been observed for the first time. With increasing particle number, the longitudinal Schottky noise spectrum becomes dominated by collective waves for cooled beams, allowing a determination of velocities of sound. After correcting for these coherent distortions fo the Schottky spectrum, the longitudinal beam temperature …

Nuclear and High Energy PhysicsBeam diameterChemistryElectronlaw.inventionIonIntrabeam scatteringlawLaser coolingPhysics::Accelerator PhysicsAtomic physicsInstrumentationStorage ringBeam (structure)Electron coolingNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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