On the Charge Dependence of the Pion-Nucleon Coupling Constant and Nucleon-Nucleon Low-Energy Scattering Parameters

The simple model describing charge independence and charge symmetry breaking of the pion-nucleon coupling constant is proposed. The model, which has simple physical meaning and foundation, suggests directly proportional dependence of the pion-nucleon coupling constants on the masses of interacting nucleons and pions. Charge dependence of the pion-nucleon coupling constant and the ${}^1{S}_0$-state low-energy nucleon-nucleon ($NN$) scattering parameters are studied on the basis of the Yukawa meson theory. The values of the $np$ and $nn$ interaction characteristics calculated by the proposed model agree quite well with the experimental data.