Photoproduction of the Theta^+ and its vector and axial-vector structure

TL;DR

This paper investigates the vector and axial-vector structure of the Theta^+ baryon using a chiral quark-soliton model, providing new calculations of coupling constants, decay widths, and scattering observables relevant to photoproduction experiments.

Contribution

It offers the first detailed analysis of the Theta^+ structure within the SU(3) chiral quark-soliton model, including corrections and predictions for experimental observables.

Findings

Calculated K^*-N-Theta coupling constants: 0.74-0.87 and 0.53-1.16.

Estimated decay width Gamma_{Theta->KN} as 0.71 MeV.

Provided differential cross sections and beam asymmetries for photoproduction.

Abstract

We present recent investigations on the vector and axial-vector transitions of the baryon antidecuplet within the framework of the self-consistent SU(3) chiral quark-soliton model, taking into account the 1/N_c rotational and linear m_s corrections. The main contribution to the electric-like transition form factor comes from the wave-function corrections. This is a consequence of the generalized Ademollo-Gatto theorem. It is also found that in general the leading-order contributions are almost canceled by the rotational 1/N_c corrections. The results are summarized as follows: the vector and tensor K^*-N-Theta coupling constants, g_{K^*-N-Theta}=0.74 - 0.87 and f_{K^*-N-Theta}=0.53 - 1.16, respectively, and Gamma_{Theta->KN}=0.71 MeV, based on the result of the K-N-Theta coupling constant g_{K-n-Theta}=0.83. We also show the differential cross sections and beam asymmetries, based on the present results. We also discuss the connection of present results with the original work by Diakonov, Petrov, and Polyakov.