Final-State Spectrum of ${}^3$He after ${\beta }^{-}$ Decay of Tritium Anions T${}^{-}$

The final-state spectrum of $\beta$ decaying tritium anions T${}^{-}$ was calculated. The wavefunctions describing the initial T${}^{-}$ ground state and the final ${}^3$He states were obtained by the full configuration-interaction method. The transition probability was calculated within the sudden approximation. The transition probability into the electronic continuum is extracted from the complex-scaled resolvent and is shown to converge for very high-energies to an approximate analytical model probability distribution.