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 [Formula presented] 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 [Formula presented].
ASJC Scopus subject areas
- Physics and Astronomy(all)