Two-photon double-electron D-wave resonant excitation in the positronium negative ion

Abstract

We present two-photon double-electron D-wave excitation in the positronium negative ion by means of demonstration of D-wave autodetaching resonances. An attempt has also been made to locate two new 1De shape resonances in positronium negative ion lying above the Ps(N = 4) threshold. The calculations are based on the framework of complex-coordinate rotation method using correlated exponential wave functions within the framework of complex-coordinate rotation method. We also present the 1De resonance parameters associated with the N = 2, 3, 4 Ps thresholds, and our results are comparable with the available data for the known states in the literature. Seven Feshbach resonances below the N = 4 Ps threshold and two shape resonances above the N = 4 Ps threshold have not been reported until now. In a broad sense, our findings and methods might be useful for the research communities of atomic physics, nuclear physics, and semiconductor quantum dots including excitons.