Bremsstrahlung process nu(tau)->nu(e)e(+)e(-) gamma - art. no. 113004

The bremsstrahlung process nu(tau)-->nu(e)e(+)e(-) gamma is the dominant ph oton-producing decay of heavy tau neutrinos with m(nu tau) >2m(e) so that t his process is instrumental for supernova 1987A constraints on the properti es of these particles, notably on their mixing amplitude with nu(e). We cal culate the rate of the bremsstrahlung process as well as the photon spectru m and the angular distribution relative to the spin direction of the parent neutrino. We carefully pay attention to the difference between Dirac and M ajorana neutrinos. [S0556-2821(98)05517-9].