Regular Article

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

¹ Department of Physics, Harbin Institute of Technology, Heilongjiang Sheng, Harbin 150001, P.R. China
² Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan

^a e-mail: skar@hit.edu.cn

Received: 26 May 2018
Received in final form: 13 September 2018
Published online: 8 November 2018

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 ¹D^e 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 ¹D^e 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.