Description of isospin mixing by a generator coordinate method

TL;DR

This paper introduces a generator coordinate method to effectively describe isospin mixing in nuclei, demonstrated on nitrogen-14, with results aligning well with experimental data, aiding nuclear reaction studies.

Contribution

A new generator coordinate approach for modeling isospin mixing in nuclei, enabling accurate description within a variational framework.

Findings

Successfully describes T=0 and T=1 states and their mixing in 14N.

Reproduces energy spectra and E1 transition strengths consistent with experiments.

Proves useful for studying alpha capture reactions in N=Z nuclei.

Abstract

Background: The isospin mixing is an interesting feature of atomic nuclei. It plays a crucial role in astrophysical nuclear reactions. However, it is not straightforward for variational nuclear structure models to describe it. Purpose: We propose a tractable method to describe the isospin mixing within a framework of the generator coordinate method and demonstrate its usability. Method: We generate the basis wave functions by applying the Fermi transition operator to the wave functions of isobars. The superposition of these basis wave functions and variationally obtained wave functions quantitatively describes the isospin mixing. Results: Using 14N as an example, we demonstrate that our method reasonably describes both T = 0 and 1 states and their mixing. Energy spectrum and E1 transition strengths are compared with the experimental data to confirm isospin mixing. Conclusion: The proposed method is effective enough to describe isospin mixing and is useful, for example, when we discuss {\alpha} capture reactions of N = Z nuclei.