Doubly Excited 1,3Po Resonance States of Ps− in Non-Ideal Plasmas

The P-wave resonance states of the positronium negative ion Ps− embedded in non-ideal classical plasmas are investigated using the stabilization method. Effective interparticle interactions are modeled via a non-ideal plasma pseudopotential accounting for both screening and correlation effects, and highly correlated exponential wave functions are used to treat many-body correlation. One 1Po resonance and two 3Po resonances, labeled 3Po(1) and 3Po(2), are identified, all located below the Ps (n = 2) threshold. Resonance energies and widths of these states are reported for screening parameters λ ≤ 0.09 and non-ideality parameters γ ≤ 0.5. Our results show that increasing plasma screening elevates resonance energies, while plasma non-ideality further modulates the evolution of these P-wave resonance states. We also determine the critical screening parameters at which each resonance state merges into the continuum.