Investigation of two-photon 2s -> 1s decay in one-electron and one-muon ions

TL;DR

This paper investigates the two-photon radiative decay of the 2s state in one-electron and one-muon ions, highlighting nuclear size effects and introducing a high-accuracy approximation for angular-differential transition probabilities.

Contribution

It introduces a two-parameter approximation for describing two-photon decay probabilities with high accuracy, accounting for polarization and nuclear size effects.

Findings

Decay behavior differs between electron and muon ions due to nuclear size corrections.

The approximation accurately describes angular and polarization properties of emitted photons.

Transition probabilities were calculated for ions with atomic numbers 1 to 120.

Abstract

We have studied the radiative decay of the 2s state of one-electron and one-muon ions, where the two-photon mechanism plays an important role. Due to the nuclear size corrections the radiative decay of the 2s state in the electron and muon ions is qualitatively different. Based on the accurate relativistic calculation, we introduced a two-parameter approximation, which makes it possible to describe the two-photon angular-differential transition probability for the polarized emitted photons with high accuracy. The emission of photons with linear and circular polarizations was studied separately. We also investigated the transition probabilities for the polarized initial and final states. The investigation was performed for ions with atomic numbers 1 < Z < 120.