Isospin-symmetry-breaking corrections to superallowed Fermi beta decay: Radial excitations

TL;DR

This paper investigates the impact of radial excitations on isospin-symmetry-breaking corrections in superallowed Fermi beta decay, revealing that these excitations significantly reduce the correction estimates used in previous models.

Contribution

It introduces a second-order renormalization approach accounting for radial excitations, which were previously neglected, providing a more accurate correction term.

Findings

Radial excitations significantly affect isospin-symmetry-breaking corrections.

The new correction term decreases previous estimates of the corrections.

The formalism enhances the precision of superallowed Fermi beta decay analyses.

Abstract

Based on an exact formalism, we study the effects of isospin-symmetry-breaking interactions on superallowed 0+ -> 0+ transitions. We calculate the second-order renormalization of the Fermi matrix element due to radial contributions and show that radial excitations neglected in the treatment of Towner and Hardy are significant. These are estimated to decrease the isospin-symmetry-breaking corrections. Our results provide a correction term that can be included in existing approaches.