0000000000555794

AUTHOR

F. Frommberger

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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Experimental Check of the Gerasimov-Drell-Hearn Sum Rule for H1

2004

For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule.

PhysicsRange (particle radiation)PhotonProton010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaNuclear TheoryGeneral Physics and AstronomyPhoton energy01 natural sciencesNuclear physicsRegge theory0103 physical sciencesHigh Energy Physics::ExperimentSum rule in quantum mechanicsNuclear Experiment010306 general physicsAstrophysics::Galaxy AstrophysicsPhysical Review Letters
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