We present cross sections for the formation of positronium chloride (PsCl) in
its ground state from the charge exchange between positronium (Ps) and chloride
(Cl−) in the range of 10 meV - 100 eV Ps energy. We have used theoretical
models based on the first Born approximation in its three-body formulation. We
simulated the collisions between Ps and Cl− using ab-initio methods at both
mean-field and correlated levels extrapolated to the complete basis set limit.
We have investigated Ps excited states up to n=4. The results suggest that
the channel Ps(n=2) is of particular interest for the production of PsCl in
the ground state, and shows that an accurate treatment of the electronic
correlation leads to a significant change in the global shape of the PsCl
production cross section with respect to the mean-field level.Comment: 13 Pages, 7 Figures, 3 Table