0000000000555793

AUTHOR

W. V. Drachenfels

showing 2 related works from this author

First Measurement of the Gerasimov-Drell-Hearn Sum Rule forH1from 0.7 to 1.8 GeV at ELSA

2003

To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] mub.

PhysicsParticle physicsRange (particle radiation)PhotonProton010308 nuclear & particles physicsNuclear TheoryGeneral Physics and AstronomyPhoton energy01 natural sciencesHelicityNuclear physics0103 physical sciencesHigh Energy Physics::ExperimentSum rule in quantum mechanicsNuclear Experiment010306 general physicsNucleonSpin-½Physical Review Letters
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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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