Perturbative calculations in a unified gauge-field model of strong, weak, and electromagnetic interactions

Abstract

We calculate several corrections to zeroth-order symmetry relations in a unified gauge-field model of strong, weak, and electromagnetic interactions. Among the topics discussed are the proton-neutron mass difference, the pion mass, the pion mass difference, and parity-violation effects. We discuss the perturbation scheme and establish the gauge invariance of the results. The pion mass originates from electromagnetic corrections and we find the value of 37 MeV. The pion mass difference is not affected by the inclusion of weak interactions and the hard-pion corrections to the mass difference are approximately 0.5 MeV.