Resonances below the Ps ( n = 2 ) excitation threshold of the e + − He ( 1 s 2 s 3 S e ) system interacting with screened potentials

We have investigated the resonances in the e + − He ( 3 S e ) system interacting with screened potentials by using the stabilization method. Two types of screened potential have been considered: static screened Coulomb potential and exponential cosine-screened Coulomb potential. A model potential has been used to describe the interaction between the outer electron and the He + ionic core. We have found two resonances below the Ps ( n = 2 ) − He + threshold. For the unscreened case, our results are in nice agreement with some of the most accurate results available in the literature.