RADIATIVE TAU-LEPTON DECAY, TAU(-)-]NU-TAU+PI(-)+GAMMA

Taking into account the contributions of Inner Bremsstrahlung and structural radiation we have analyzed the energy distributions of particles produced in radiative tau-lepton decay for unpolarized tau. A method is developed to study the polarization properties of produced photons. The presence of radiative zeros along the line u = O, u being the effective mass square of gamma + nu(tau)-system, for Inner Bremsstrahlung probability is proved in general form. The weak form factors which are defined as the structural part of matrix element are parametrized in terms of rho- and alpha(1)-meson contributions. The conservation of vector current hypothesis together with experimental data from the radiative pi(+/-)-decay allows us to define both form factors in the whole time-like region for the tau-decay. Sensitivity of effective pi(-) + gamma-mass spectrum to the sign of form factor nu(t) was demonstrated in a wide region of momentum transfer. The study of E(gamma) dependence of the Dalitz-distribution d(2)W/dE(gamma) dE pi at fixed (E(gamma) + E(pi)) is shown to be sufficient for reconstruction of both form factors nu(t) and alpha(t), including not only their absolute values but the t-dependence of their phases as well. (C) 1995 Academic Press, Inc.