The parity-violating pion-nucleon coupling constant from a realistic three flavor Skyrme model

Abstract

We study the parity-violating pion-nucleon coupling $G_{\pi }$ in the framework of a realistic three flavor Skryme model. We find a sizeable enhancement of $G_{\pi }\simeq \mathrm{0.8...1.3}\cdot 10^{-7}$ compared to previous calculations in two-flavor models with vector mesons. This strangeness enhancement stems from induced kaon fields of the chiral soliton and the non-monotoneous dependence on symmetry breaking of the nucleon matrix element of the flavor singlet piece of the operator associated with these induced fields. Both features are sensitive to four quark operators including an $\bar{s}s$ pair.

Comments: 10 pp, LaTeX, uses epsf, 2 figs, small corrections plus additional explanations, value of Gpi somewhat smaller