The μ → e + γ decay and the intermediate charged vector boson theory

Abstract

The μ-e-γ vertex is calculated in the intermediate charged vector boson theory, as a function of the square of the four momentum of the photon. Consistency arguments show that the boson anomalous magnetic moment should be taken equal to zero. The result is then specialized to a real photon. The experimental branching ratio $$\varrho = (\mu \to e + \gamma )/(\mu \to e + v + \bar v) = 1.2 \pm 1.5$$ fixes the cut-off value at less than one fifth the intermediate boson mass. It is concluded that this theory does not reasonably account for the experimental data, no matter how massive the boson is assumed to be.