Compton scattering by the proton^*
Abstract
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 \gamma_\pi=(-37.9 \pm 0.6(stat+syst) \pm 3.5(model))x10^{-4}fm^4.
- Publication:
-
Physics Letters B
- Pub Date:
- March 2001
- DOI:
- 10.1016/S0370-2693(01)00231-3
- arXiv:
- arXiv:nucl-ex/0102003
- Bibcode:
- 2001PhLB..503..245G
- Keywords:
-
- Nuclear Experiment;
- High Energy Physics - Phenomenology
- E-Print:
- Phys.Lett.B503:245-255,2001