Quantum chemical contribution to electron neutrino mass determination

Theoretical data have been obtained needed to analyze the experimental measurements of the T 2 β‐decay energy distribution near the end point. The energies of the six lowest 1 ∑ + states of HeT + have been computed for internuclear distances 1.0 ≦4 R ≦ 4.0 bohr. The wavefunctions have been used to calculate the transition probabilities to these states from the electronic ground state of T 2 . Distribution of the probabilities over the final vibrational and rotational states has been evaluated including rotationally predissociating resonances. Using the stabilization method the 1 ∑ + resonance states of HeT + above the ionization limit have been investigated. Preliminary potential energy curves for several of these states have been determined for a wide range of internuclear distances.