A chiral quark model for meson electro-production in the region of D-wave resonances

TL;DR

This paper extends a chiral quark model to calculate meson scattering and electroproduction amplitudes in D-wave resonances, incorporating various meson-baryon interactions within a coupled-channel framework.

Contribution

It introduces a coupled-channel formalism for D-wave resonances using the Cloudy Bag Model, expanding previous work on lower partial waves with detailed meson-baryon vertices.

Findings

Amplitudes are consistent across channels but weaker than experimental data.

The model reproduces resonance widths with parameter adjustments.

Discrepancies suggest limitations in current quark model approaches.

Abstract

The meson scattering and electroproduction amplitudes in the D13, D33 and D15 partial waves are calculated in a coupled-channel formalism incorporating quasi-bound quark-model states, extending our previous studies of the P11, P33 and S11 partial waves. The vertices of the baryon-meson interaction including the s- and d-wave pions and $\rho$-mesons, the s-wave $\eta$-meson, and the $s$- and p-wave $\sigma$-mesons are determined in the Cloudy Bag Model, with some changes of the parameters to reproduce the widths of the resonances. The helicity amplitudes and the electroproduction amplitudes exhibit consistent behavior in all channels but tend to be too weak compared to the experiment. We discuss possible origins of this discrepancy which arises also in the constituent quark model calculations.