Molecular effects in tritiumβdecay. II. Rotation-vibration excitation, dissociation, and rotational predissociation in the decay of theT2and TH molecules

Probabilities have been computed for transitions induced by a β-decay process from the ground rovibronic state of the ${\mathrm{T}}_2$ molecule to various bound rovibrational and scattering states connected with the first six ${}_{}{}^1{}_{}{}^{}\mathrm{\Sigma }_{}^{+}{}_{}{}^{}$ electronic states of the ${}_{}{}^3{}_{}{}^{}$ ${\mathrm{HeT}}^{+}$ ion. Analogous calculations were performed for the TH source but only the ground electronic state of the daughter system was considered. For transitions from the ${\mathrm{T}}_2$ source to the ground electronic state of the daughter ion a probability equal to 0.4083 is associated with bound rovibrational states while 0.1659 is associated with scattering states. The same values for the TH source are 0.5572 and 0.0136, respectively. It is shown that the use of a TH source is not advantageous in a neutrino-mass experiment. Numerical accuracies of our calculations have been checked by making extensive use of sum rules. The total error in the final result is discussed.