Quark Model Study of The eta Photoproduction: Evidence for a New S11 Resonance?

TL;DR

This study uses a chiral constituent quark model to analyze eta photoproduction data, providing evidence for a new S11 resonance at 1.729 GeV and extracting key resonance properties.

Contribution

It introduces a systematic analysis revealing a new S11 resonance and determines its properties, enhancing understanding of nucleonic resonances in eta photoproduction.

Findings

Evidence for a new S11 resonance at 1.729 GeV

Determined the resonance's total width as 183 MeV

Extracted configuration mixing angles and decay widths

Abstract

An extensive and systematic study of the recent eta photoproduction 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 eta N 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.