Inner Bremsstrahlung inμ-Meson Decay

The transition probability for the decay of a $\mu$-meson resulting in the simultaneous ejection of an electron and a photon is computed. Its dependence on the energies of the two emitted particles and on the angle between their direction of emission is given for the general case of an arbitrary mixture of three basic Fermitype interactions for the $\mu$-decay process.