First measurement of the Gerasimov-Drell-Hearn integral for H-1 from 200 to 800 MeV

ISSN
0031-9007
Date Issued
2001
Author(s)
Ahrens, J.
Altieri, S.
Annand, JRM
Anton, G.
Arends, H. J.
Aulenbacher, K.
Beck, R.
Bradtke, C.
Braghieri, A.
Degrande, N.
d'Hose, N.
Dutz, H.
Goertz, S.
Grabmayr, P.
Hansen, K.
Harmsen, J.
von Harrach, D.
Hasegawa, S.
Hasegawa, T.
Heid, E.
Helbing, Krister
Holvoet, H.
van Hoorebeke, L.
Horikawa, N.
Iwata, T.
Jennewein, P.
Kageya, T.
Kiel, B.
Klein, F.
Kondratiev, R.
Kossert, K.
Krimmer, J.
Lang, M.
Lannoy, B.
Leukel, R.
Lisin, V.
Matsuda, T.
McGeorge, J. C.
Meier, A.
Menze, D.
Meyer, Werner
Michel, Tanja Maria
Naumann, J.
Owens, R. O.
Panzeri, A.
Pedroni, P.
Pinelli, T.
Preobrajenski, I.
Radtke, E.
Reichert, E.
Reicherz, G.
Rohlof, C.
Ryckbosch, D.
Sadiq, F.
Schoch, B.
Schumacher, M.
Seitz, Bjoern
Speckner, T.
Steigerwald, M.
Takabayashi, N.
Tamas, Gabor
Thomas, Andy
van de Vyver, R.
Wakai, A.
Weihofen, W.
Wissmann, F.
Zapadtka, F.
Zeitler, G.
DOI
10.1103/PhysRevLett.87.022003
Abstract
A direct measurement of the helicity dependence of the total photoabsorption cross section an the proton was carried out at MAMI (Mainz) in the energy range 200 < E-<gamma> < 800 MeV. The experiment used a 4<pi> 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 gamma (0) determined from the data are 226 +/- 5(stat) +/- 12(syst) mub and -187 +/- 8(stat) +/- 10(syst) x 10(-6) fm(4), respectively, for 200 < E-<gamma> < 800 MeV.