Bound-state properties, positron annihilation and hyperfine structure of the four-body positronium hydrides

Abstract

Bound-state properties of the ground (bound) -state(s) in the four-body positronium hydrides HPs, HPs (DPs), HPs (TPs) and MuPs are determined and investigated. By using numerical data from our computations of these four-body systems, we have determined a number of different annihilation rates for each of these positronium hydrides and evaluated the hyperfine structure splitting. The properties of the ground (bound) states in the four-body exitonic complexes, where and , have also been evaluated numerically. The neutral four-body systems with are similar to the HPs hydrides. In particular, each of these states has only one bound state. We also discuss applications of the exponential and semi-exponential variational expansions for accurate, bound state computations of the four-body positronium hydrides.