Calculations based on the projection method and using explicitly correlated Gaussians are used to confirm the existence of positron attachment to two doubly excited states of helium. The e+He(2s2 1Se) and e +He(3s2 1Se) states have binding energies of 0.449 and 0.286 eV. These estimates of the resonance energies are nearer to the variational limit than previous calculations. These states will exist as resonances in the e +-He scattering continuum, and complex rotation calculations have been used to estimate their widths.
|Number of pages
|Physical Review A - Atomic, Molecular, and Optical Physics
|Published - Aug 2013