Two-phonon structures for beta-decay theory

TL;DR

This paper investigates the beta-decay of $^{60}$Ca using a microscopic model with phonon interactions, predicting decay half-life and emission probabilities, and analyzing spectral properties with random matrix theory.

Contribution

It introduces a phonon-phonon coupling model for beta-decay, providing new predictions for decay properties and applying spectral analysis techniques.

Findings

Predicted $^{60}$Ca half-life of 0.3 ms.

Total $eta x n$ emission probability of 6.1%.

Observed redistribution of Gamow-Teller strength due to phonon coupling.

Abstract

The $\beta$-decay rates of $^{60}$Ca have been studied within a microscopic model, which is based on the Skyrme interaction T45 to construct single-particle and phonon spaces. We observe a redistribution of the Gamow-Teller strength due to the phonon-phonon coupling, considered in the model. For $^{60}$Sc, the spin-parity of the ground state is found to be $1^+$. We predict that the half-life of $^{60}$Ca is 0.3 ms, while the total probability of the $\beta x n$ emission is 6.1%. Additionally, the random matrix theory has been applied to analyse the statistical properties of the $1^+$ spectrum populated in the $\beta$-decay to elucidate the obtained results.