Bibcode
Vegna, V.; Bellini, V.; Bocquet, J. P.; Casano, L.; D'Angelo, A.; di Salvo, R.; Fantini, A.; Franco, D.; Gervino, G.; Ghio, F.; Giardina, G.; Girolami, B.; Giusa, A.; Ignatov, A. S.; Lapik, A.; Lleres, A.; Levi Sandri, P.; Mammoliti, F.; Mandaglio, G.; Manganaro, M.; Moricciani, D.; Mushkarenkov, A. N.; Nedorezov, V. G.; Randieri, C.; Rebreyend, D.; Rudnev, N. V.; Russo, G.; Schaerf, C.; Sperduto, M. L.; Sutera, M. C.; Turinge, A.
Bibliographical reference
International Journal of Modern Physics E, Volume 19, Issue 05-06, pp. 1241-1248 (2010).
Advertised on:
2010
Citations
1
Refereed citations
1
Description
The study of meson photoproduction on the nucleon is a very important
tool to complete the puzzle of baryon excited states. GRAAL aim is the
measurement of cross sections and of beam asymmetries for all the
photonuclear reactions accessible in the energy range from 600 MeV up to
1.5 GeV. In the following preliminary results of the Σ beam
asymmetry for ω photoproduction on the free proton in Hydrogen and
on the quasi-free nucleon in Deuterium are shown. GRAAL is the first
experiment in which both the charged and the radiative decay of ω
meson are studied. Since the beam asymmetry is independent of the decay
mode, the comparison of the results from the two channel allows an
important check on data consistency. Results on the free proton are in
good agreement with theoretical prediction from Zhao model and confirm
the presence of P13(1720) state. The analysis performed for
the radiative decay is applied to the process of ω photoproduction
on the quasi free nucleon in Deuterium.