Relativistic coupled-cluster single-double calculations of positron-atom bound states

TL;DR

This paper employs relativistic coupled-cluster methods to calculate positron binding energies to various atoms, providing theoretical predictions that can guide experimental searches for positron-atom bound states.

Contribution

It introduces a relativistic coupled-cluster single-double approach for calculating positron-atom bound states, extending previous work to open-shell transition metals.

Findings

Accurate positron binding energies for closed-shell atoms like Be, Mg, Ca, Zn, Cd, Hg.

Predictions of positron binding energies for open-shell transition metals from Sc to Pt.

Identification of Feshbach resonances useful for experimental detection.

Abstract

Relativistic coupled-cluster single-double approximation is used to calculate positron-atom bound states. The method is tested on closed-shell atoms such as Be, Mg, Ca, Zn, Cd, and Hg where a number of accurate calculations is available. It is then used to calculate positron binding energies for a range of open-shell transition metal atoms from Sc to Cu, from Y to Pd, and from Lu to Pt. These systems possess Feshbach resonances, which can be used to search for positron-atom binding experimentally through resonant annihilation or scattering.