The destruction of (3)HeT(+) in collisions with tritium: a dynamical study.

The dynamics of the T + HeT= 0, = 0 → T + He reaction has been theoretically investigated by means of quantum, statistical and quasi-classical methods on a recently refined potential energy surface. Integral cross sections, rotational distributions, differential cross sections and rate constants have been obtained. The destruction following the above reaction of HeT, an ionic species formed during the single-β decay of the molecular tritium, is thus studied in detail, and its possible influence on current experiments to estimate the mass of the neutrino discussed. In this sense, values of the rate constant for such a process between 10 and 500 K have been predicted to be around 1.2 × 10 cm s. The thermal rate constant, obtained by considering also the rates for the processes initiated from the five first rotational states HeT= 0, = 1-5, confirms such a value.