Compton Scattering by the Proton

• Main Authors: Galler, G, Lisin, V, Kondratiev, R, Massone, A. M, Wolf, S, Ahrens, J, Arends, H. -J, Beck, R, Camen, M, Capitani, G. P, Grabmayr, P, Hall, S. J, Härter, F, Hehl, T, Jennewein, P, Kossert, K, L'vov, A. I, Molinari, C, Ottonello, P, Peise, J, Preobrajenski, I, Proff, S, Robbiano, A, Sanzone, M, Schumacher, M, Schmitz, M, Wissmann, F
• Format: Journal Article
• Language: English
• Published: 06.02.2001
• Subjects: Physics - High Energy Physics - Phenomenology; Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.nucl-ex/0102003

Phys.Lett.B503:245-255,2001 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.