A new Po1 shape resonance in Ps− above the Ps(N = 3) threshold

In this study, we have located a new Po1 shape resonance in positronium ion lying above the Ps(N=3) threshold using the complex coordinate rotation method based on correlated exponential wave functions. To trace this shape resonance pole from H− to Ps−, we have calculated the shape resonance in terms of nuclear mass by changing the mass of the positively charged particle from infinitely heavy to one unit of the electron mass. The Po1 shape resonance in H− lying above the H(N=3) threshold is in accord with the available data in the literature. Our present findings are useful references for future experimental investigations to observe this new shape resonance in Ps−. The present work is also of interest in various research areas such as nuclear physics and semiconductor quantum dots including excitons.