Comparative tests of isospin-symmetry-breaking corrections to superallowed 0+-to-0+ nuclear beta decay

TL;DR

This paper evaluates different theoretical calculations of isospin-symmetry-breaking corrections in nuclear beta decay by testing their consistency with the conservation of the vector current, favoring a shell model approach.

Contribution

It introduces a quantitative test for assessing the accuracy of calculated isospin-symmetry-breaking corrections in superallowed beta decay.

Findings

Only the shell model with Saxon-Woods wave functions passes the test.

The test confirms the validity of the shell model approach for these corrections.

Other calculation methods do not satisfy the conservation of the vector current.

Abstract

We present a test with which to evaluate the calculated isospin-symmetry-breaking corrections to superallowed 0+-to-0+ nuclear beta decay. The test is based on the corrected experimental Ft values being required to satisfy conservation of the vector current (CVC). When applied to six sets of published calculations, the test demonstrates quantitatively that only one set -- the one based on the shell model with Saxon-Woods radial wave functions -- provides satisfactory agreement with CVC. This test can easily be applied to any sets of calculated correction terms that are produced in future.