Antiproton low-energy collisions with Ps-atoms and true muonium atoms ($\mu^+\mu^-$)

Abstract

Three-charge-particle collisions with participation of ultra-slow antiprotons ($\bar{\rm{p}}$) is the subject of this work. Specifically we compute the total cross sections and corresponding thermal rates of the following three-body reactions: $\bar{\rm p}+(e^+e^-) \rightarrow \bar{\rm{H}} + e^-$ and $\bar{\rm p}+(\mu^+\mu^-) \rightarrow \bar{\rm{H}}_{\mu} + \mu^-$, where $e^-(\mu^-)$ is an electron (muon) and $e^+(\mu^+)$ is a positron (antimuon) respectively, $\bar{\rm{H}}=(\bar{\rm p}e^+)$ is an antihydrogen atom and $\bar{\rm{H}}_{\mu}=(\bar{\rm p}\mu^+)$ is a muonic antihydrogen atom, i.e. a bound state of $\bar{\rm{p}}$ and $\mu^+$. A set of two-coupled few-body Faddeev-Hahn-type (FH-type) equations is numerically solved in the framework of a modified close-coupling expansion approach.