Measurement of the Induced Pseudoscalar Coupling Via Radiative Muon Capture on Hydrogen

Abstract

A pure weak interaction such as muon decay μ → ev $\overline{v}$ is characterized by a V-A amplitude. When hadrons participate the strong force induces additional couplings and the reaction is classified as semi-leptonic. These additional couplings are real due to time reversal invariance. The scalar and tensor couplings are expected to vanish because these currents have the wrong G-parity and experimentally non-zero values have not been found. In beta decay n → pe $\overline{v}$ the renormalized axial vector strength, g _a , and the weak magnetism strength, g _m , which is predicted by CVC, are accurately measured.