First measurement of the Gerasimov-Drell-Hearn integral for Hydrogen from 200 to 800 MeV
May, 2001Citations per year
Abstract: (arXiv)
A direct measurement of the helicity dependence of the total photoabsorption cross section on the proton was carried out at MAMI (Mainz) in the energy range 200 < E_gamma < 800 MeV. The experiment used a 4 detection system, a circularly polarized tagged photon beam and a frozen spin target. The contributions to the Gerasimov-Drell-Hearn sum rule and to the forward spin polarizability determined from the data are 226 \pm 5 (stat)\pm 12(sys) \mu b and -187 \pm 8 (stat)\pm 10(sys)10^{-6} fm^4, respectively, for 200 < E_\gamma < 800 MeV.Note:
- 6 pages, 3 figures, 3 tables
- photon p: interaction
- photon: polarized beam
- photon: tagged beam
- polarized target
- photon: absorption
- pi: photoproduction
- cross section: helicity
- sum rule: Drell-Hearn-Gerasimov
- p: polarizability
- four-pi-detector: experimental results
References(29)
Figures(3)