0000000000225537

AUTHOR

H.-j. Arends

showing 8 related works from this author

Compton Scattering by the Proton

2001

Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\gamma < 800 MeV and photon scattering angles 30^0 < \theta^{lab}_\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The data are in good agreement with the dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. From the subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to the multipole E2/M1 ratio EMR(340 MeV) =(-1.6 \pm 0.4(stat+syst) \pm 0.2(model)%. From all data below 455 MeV the proton's backward spin polarizability was determined to be …

PhysicsNuclear and High Energy PhysicsPhotonProton010308 nuclear & particles physicsNuclear TheoryCompton scatteringFOS: Physical sciences7. Clean energy01 natural sciencesResonance (particle physics)Scattering amplitudeNuclear physicsHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Polarizability0103 physical sciencesPhysics::Accelerator PhysicsHigh Energy Physics::ExperimentNuclear Experiment (nucl-ex)010306 general physicsMultipole expansionNuclear ExperimentNuclear ExperimentSpin-½
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Measurement of Helicity-Dependent Photoabsorption Cross Sections on the Neutron from 815 to 1825 MeV

2005

Helicity-dependent total photoabsorption cross sections on the deuteron have been measured for the first time at ELSA (Bonn) in the photon energy range from 815 to 1825 MeV. Circularly polarized tagged photons impinging on a longitudinally polarized LiD target have been used together with a highly efficient 4pi detector system. The data around 1 GeV are not compatible with predictions from existing multipole analyses. From the measured energy range an experimental contribution to the GDH integral on the neutron of [33.9 +/- 5.5(stat) +/- 4.5(syst)] microb is extracted.

PhysicsRange (particle radiation)Photon010308 nuclear & particles physicsNuclear TheoryGeneral Physics and AstronomyPhoton energy7. Clean energy01 natural sciencesHelicityNuclear physicsDeuterium0103 physical sciencesNeutronAtomic physicsNuclear Experiment010306 general physicsMultipole expansionCircular polarizationPhysical Review Letters
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Incoherent neutral pion photoproduction on 12C.

2007

We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The C-12(gamma,pi(0))C-12(4.4 MeV)* reaction has been studied with the Glasgow photon tagger at MAMI employing a new technique which uses the large solid angle Crystal Ball detector both as a pi(0) spectrometer and to detect decay photons from the excited residual nucleus. The technique has potential applications to a broad range of future nuclear measurements with the Crystal Ball and similar detector systems elsewhere. Such data are sensitive to the propagation of the Delta in the nuclear medium and will give the first information on matter transition form fa…

PhysicsNuclear reactionPhotonMesonmeasurement of incoherent photoproduction010308 nuclear & particles physicsHadronNuclear TheoryGeneral Physics and AstronomyElementary particle01 natural sciences7. Clean energyNuclear physicsPionExcited state0103 physical sciencesAtomic physics010306 general physicsNuclear ExperimentCrystal BallPhysical review letters
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Measurement of the Gerasimov-Drell-Hearn Integrand forH2from 200 to 800 MeV

2006

A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range $200l{E}_{\ensuremath{\gamma}}l800\text{ }\text{ }\mathrm{MeV}$. The experiment used a $4\ensuremath{\pi}$ detection system, a circularly polarized tagged photon beam and a frozen-spin target which provided longitudinally polarized deuterons. The contribution to the Gerasimov-Drell-Hearn sum rule for the deuteron determined from the data is $407\ifmmode\pm\else\textpm\fi{}20(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}24(\mathrm{syst})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$ for $200l{E}_{\ensuremath{\gamma}}l800\text{ }\text{ }\m…

PhysicsParticle physicsMeson production010308 nuclear & particles physicsNuclear TheoryGeneral Physics and AstronomyComputer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing)01 natural sciencesHelicityNuclear physics0103 physical sciencesSum rule in quantum mechanicsPhoton beamNuclear Experiment010306 general physicsEnergy (signal processing)Physical Review Letters
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Helicity dependence of the total inclusive cross section on the deuteron

2009

Abstract A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200 E γ 800 MeV . The experiment used a 4 π detection system, a circularly polarized tagged photon beam and a frozen spin target which provided longitudinally polarized deuterons. These new results are a significant improvement on the existing data and allow a detailed comparison with state-of-the-art calculations.

PhysicsAngular momentumRange (particle radiation)Nuclear and High Energy PhysicsNuclear TheoryPolarization (waves)HelicityDeuteron photoabsorptionCharged particleNuclear physicsCross section (physics)DeuteriumPhysics and AstronomyDouble polarization experimentSpin (physics)Nuclear ExperimentPhysics Letters B
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Compton Scattering by the Proton using a Large-Acceptance Arrangement

2001

Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV lt or approximately=E/sub gamma / lt or approximately=800 MeV and photon scattering angles 30 degrees lt or approximately= theta /sub gamma //sup lab/ lt or approximately=150 degrees , using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The previously existing data base on proton Compton scattering is greatly enlarged by more than 700 new data points. The new data are interpreted in terms of dispersion theory based on the SAID-SM99K parametrization of photo-meson amplitudes. It is found that two-pion exchange in the t-channel is needed for a descripti…

Nuclear and High Energy PhysicsProtonNuclear TheoryFOS: Physical sciencesValue (computer science)01 natural sciencesResonance (particle physics)High Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)High Energy Physics - Phenomenology (hep-ph)Dispersion relation0103 physical sciencesNuclear Experiment (nucl-ex)010306 general physicsNuclear ExperimentNuclear ExperimentQCSpin-½Physics010308 nuclear & particles physicsCompton scatteringHigh Energy Physics - PhenomenologyAmplitudeHigh Energy Physics::ExperimentMultipole expansion
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"Table 1" of "Compton scattering from the free and bound proton at backward angles above pi threshold."

2000

No description provided.

Single Differential Cross SectionPhotoproduction1.12-1.284GAMMA P --&gt; P GAMMAExclusiveDSIG/DOMEGA
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"Table 1" of "Angular and polarization dependence of Compton scattering from He-4 in the Delta resonance region"

1999

Axis error includes +- 0.0/0.0 contribution.

PhotoproductionAsymmetry MeasurementExclusiveGAMMA HE --&gt; HE GAMMAASYM
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