Eur. Phys. J. A 11, 217-230 (2001)
Quark model study of the photo-production:
Evidence for a new S11 resonance?B. Saghai1 and Z. Li2
1 Service de Physique Nucléaire, DAPNIA - CEA/Saclay, F-91191 Gif-sur-Yvette Cedex, France
2 Physics Department, Peking University, Beijing 100871, P.R. China
(Received: 14 February 2001 / Revised version: 22 June 2001 Communicated by V. Vento)
An extensive and systematic study of the recent photo-production data up to 1.2 GeV is presented within a chiral constituent quark model. A model embodying all known nucleonic resonances shows clear need for a yet undiscovered third S11 resonance in the second resonance region, for which we determine the mass (1.729 GeV) and the total width (183 MeV). Furthermore, we extract the configuration mixing angles, an important property of the quark-quark interaction in the quark model, for the resonances S11(1535) and S11(1650), as well as for the resonances D13(1520) and D13(1700). Our results agree well with the quark model predictions. In addition, the partial decay widths and/or the photo-excitation helicity amplitudes for the nucleonic resonances S11(1535), S11(1650), P11(1710), P13(1720), D13(1520), D13(1700), D15(1675), and F15(1680) are also obtained in this approach.
12.39.Fe - Chiral Lagrangians.
13.40.Hq - Electromagnetic decays.
13.60.Le - Meson production.
14.20.Gk - Baryon resonances with S=0 .
© Società Italiana di Fisica, Springer-Verlag 2001