Compton scattering by the proton

ISSN
0370-2693
Date Issued
2001
Author(s)
Galler, G.
Lisin, V.
Kondratiev, R.
Massone, A. M.
Ahrens, J.
Arends, H. J.
Beck, R.
Camen, M.
Capitani, G. P.
Grabmayr, P.
Hall, S. J.
Harter, Frauke V.
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.
DOI
10.1016/S0370-2693(01)00231-3
Abstract
Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV less than or similar to E-gamma less than or similar to 800 MeV and photon scattering angles 30 degrees less than or similar to theta (lab)(gamma) less than or similar to 150 degrees, 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 +/- 0.4(stat+syst) +/- 0.2(model))% From all data below 455 MeV the proton's backward spin polarizability was determined to be gamma pi = (-37.9 +/- 0.6(stat+syst) +/- 3.5(model)) x 10(-4) fm(4). (C) 2001 Elsevier Science B.V. All rights reserved.