Chiral model of the nucleon andΔisobar: The coherent-pair approximation

Publisher Website
Google Scholar
Abstract
The linear chiral σ model with quark fields and elementary pion and σ fields is used to describe static properties of the nucleon and the Δ resonance. To this end baryon Fock states with good spin and isospin are constructed from summations of components in which three quarks in s states with the SU(2)×SU(2) quantum numbers of the nucleon and Δ are coupled to multipion states and a scalar-isoscalar coherent state of the σ fields. The multipion states are constructed to have coherent properties as well as definite spin-isospin quantum numbers. Ignoring the effects of vacuum polarization the baryon energy is made stationary, resulting in a set of four coupled nonlinear eigenvalue equations and a diagonalization procedure between frozen fields. The corresponding solitonic solutions are used to evaluate the relevant nucleon properties. A comparison is made with the results from the cloudy-bag model, the projected mean-field chiral-soliton model, and the Skyrme approach.

This publication has 31 references indexed in Scilit: