Helicity dependence of the gamma p -> N pi channels and multipole analysis in the Delta region

ISSN
1434-6001
Date Issued
2004
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.
Drechsel, D.
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.
Panzeri, A.
Pedroni, P.
Pinelli, T.
Preobrajenski, I.
Radtke, E.
Reichert, E.
Reicherz, G.
Rohlof, C.
Rosner, G.
Ryckbosch, D.
Schoch, B.
Schumacher, M.
Seitz, Bjoern
Speckner, T.
Takabayashi, N.
Tamas, Gabor
Thomas, Andy
Tiator, L.
van de Vyver, R.
Wakai, A.
Weihofen, W.
Wissmann, F.
Zapadtka, F.
Zeitler, G.
DOI
10.1140/epja/i2003-10216-x
Abstract
A high-quality double-polarization data set for the helicity dependence of the total and differential cross-sections for both gammap --> Npi channels in the Delta region has been obtained in the framework of the GDH experiment. The experiment, performed at the Mainz microtron MAMI, used a 4pi detection system, a circularly polarized photon beam, and a longitudinally polarized frozen-spin target. These data are included in the database to perform a multipole analysis to determine the properties of the Delta(1232)-resonance. For the resonant Delta(1232) multipoles we find a very good agreement with previous analyses, while the nonresonant ones show significant deviations.