Positron annihilation in the dense plasma-embedded Ps−

We have made a first investigation on the annihilation rates of the positronium negative ion (Ps−) embedded in dense plasma environments. The one-, two- and three-photon annihilation rates and the ground-state energies of Ps− are reported for various Debye lengths along with the ground-state energies of the Ps atom. (Ps−) → nγ + e−.