Abstract
Recent observations on resonance states of the positronium negative ion (Ps−) in the laboratory created huge interest in terms of the calculation of the resonance parameters of the simple three-lepton system. We calculate the resonance parameters for the doubly excited 1P° states in Ps− using correlated exponential wave functions based on the complex-coordinate rotation method. The resonance energies and widths for the 1P° Feshbach resonance states in Ps− below the N = 2, 3, 4, 5 Ps thresholds are reported. The 1P° shape resonance above the N = 2, 4 Ps thresholds are also reported. Our predications are in agreement with the available results. Few Feshbach resonance parameters below the N = 4 and 5 Ps thresholds have been reported in the literature. Our predictions will provide useful information for future resonance experiments in Ps−.
Highlights
The study of doubly excited resonance states (DERS) in Ps− has found significant relevance since the experimental observations of Michishio et al [1] for a 1 P◦ shape resonance in Ps− near the N = 2 positronium (Ps) threshold
The DERS that appear from the closed channel and open channel segments of the scattering wave functions are commonly known, respectively, as Feshbach resonances and shape resonances
The 1 P◦ Feshbach resonances in Ps− below the N = 2 Ps threshold have been studied by Botero [18] using the adiabatic treatment in hyperspherical coordinates (ATHC), and by Bhatia and Ho [19], using the coordinate rotation method (CRM)
Summary
The study of doubly excited resonance states (DERS) in Ps− has found significant relevance since the experimental observations of Michishio et al [1] for a 1 P◦ shape resonance in Ps− near the N = 2 positronium (Ps) threshold. We will briefly summarize previous works studying the doubly-excited 1 P◦ resonance states, as these DERS are of our present interest. The 1 P◦ Feshbach resonances in Ps− below the N = 2 Ps threshold have been studied by Botero [18] using the ATHC, and by Bhatia and Ho [19], using the CRM with Hylleraas-type wave functions (HW). Ho and Bhatia [20] studied the doubly excited 1 P◦ Feshbach resonance states below the N = 3, 4, 5, 6 Ps thresholds using the HW based on the CRM. Throughout this paper, the RP are meant for resonance energies and total widths, and atomic units (a.u.) are used unless stated otherwise
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
