Doubly excited resonance states of helium in exponential cosine-screened Coulomb potentials

Abstract

We have made an investigation on the $2{s}^{2}\text{ }{^{1}S}^{e}$ resonances in helium (He) in exponential cosine-screened Coulomb potentials (ECSCP). Highly correlated wave functions are used to take into account of the correlation effect of the charged particles. Resonance energies and widths for the doubly excited He in ECSCP are determined using the stabilization method by calculating the density of the resonance states. Results for resonance energies and widths are reported for the screening parameter in the range 0.0--0.275