Beyond the soft photon approximation in radiative production and decay of charged vector mesons

We study the effects of model-dependent contributions and the electric quad rupole moment of vector mesons in the decays V- --> P(-)P(0)gamma and tau ( -) --> nuW(-)gamma. Their interference with the amplitude originating from the radiation due to electric charges vanishes for photons emitted collinea rly to the charged particle in the final state. This brings further support to our claim in previous works, that measurements of the photon energy spe ctrum for nearly collinear photons in those decays are suitable for a first measurement of the magnetic dipole moment of charged vector mesons.