Relation between vector and axial-vector Cabibbo angles in brokenSU 3 symmetry

Abstract

The renormalization of the weak axial-vector coupling constant in the decay $$\Xi ^0 \to \Sigma ^ + + e^ - + \bar \nu $$ is calculated on the basis of the assumption that theSU 3 breaking is unimportant at high energies and the result used to show that the equality of the vector and axial-vector Cabibbo angles, which is expected to hold in the limit of exactSU 3 symmetry, is preserved by the symmetry breaking.