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

TL;DR

This paper calculates cross sections and rates for low-energy antiproton collisions with positronium and true muonium atoms, using advanced few-body equations to understand these rare three-body interactions.

Contribution

It introduces a numerical method solving coupled Faddeev-Hahn equations for three-body antiproton collision processes involving exotic atoms.

Findings

Computed total cross sections for $ar{ m p}+(e^+e^-)$ and $ar{ m p}+( ext{mu}^+ ext{mu}^-)$ reactions.

Determined thermal rates for formation of antihydrogen and muonic antihydrogen.

Applied a modified close-coupling approach to solve few-body equations.

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.