Aspects of the chiral quark model

Abstract

We point out intriguing connections between the chiral quark model in which the nucleon is treated as a soliton and the ordinary potential-binding quark model. The axial-vector coupling comes out near the value (5/3 rather than around 0.7 as in the Skyrme description and can be easily ‘‘fine-tuned’’ to its experimental value. A ‘‘linear potential’’ in some sense is generated as a collective effect of the ‘‘meson cloud.’’ Contact with QCD is made by introducing a gluonium field so as to satisfy the trace-anomaly equation. In the simplest treatment of this field one predicts a scalar-isoscalar state at 900 MeV in agreement with a recent analysis of experiments. The model is used to discuss how a ‘‘nontrivial winding number’’ emerges for the meson fields. A number of additional features of the model are treated.