A proposed solution for the lifetime puzzle of the 229mTh+ isomer

TL;DR

This paper investigates the lifetime discrepancy of the 229Th+ isomer by analyzing resonance conversion mechanisms, ambient effects, and electronic level fragmentation, proposing a solution to the thorium puzzle.

Contribution

It introduces a new explanation for the lifetime puzzle by considering environmental effects and electronic structure fragmentation, aligning theory with experimental data.

Findings

Lifetime depends on ambient conditions.

Fragmentation of electron levels enhances resonance interactions.

The proposed model reduces the theoretical lifetime to match experiments.

Abstract

With the example of the 229Th nucleus, which is the most likely candidate for the creation frequency standard of a future, the dynamics of the interplay and the relationship of various resonance conversion mechanisms is analyzed. As a result, a solution is proposed for the so-called thorium puzzle, which consisted of a contradiction between the experimental and theoretical lifetimes of Th+ ions. First, the solution demonstrates the dependence of the lifetime of the nuclear isomer on the ambient conditions. Second, it demonstrates the leveling role of the fragmentation of the single-electron levels, which makes the resonance amplification of the electron-nuclear interaction more likely. Both of these trends lead to a probable decrease of the theoretical lifetime towards agreement with experiment.