Mirror energy differences in T=1/2 f7/2-shell nuclei within isospin-dependent density functional theory

Background: Small asymmetry between neutrons and protons, caused by the differences in masses and charges of the up and down constituent quarks, leads to isospin symmetry breaking. The isospin nonconservation affects a broad range of observables from superallowed Fermi weak interaction to isospin-forbidden electromagnetic rates. Its most profound and cleanest manifestation are systematic shifts in masses and excitation energies of mirror atomic nuclei. Purpose: Recently, we constructed the charge-dependent density functional theory (DFT) that includes class II and III local interactions and demonstrated that the model allows for very accurate reproduction of mirror and triplet displacement energies in a very broad range of masses. The aim of this work is to further test the chargedependent functional by studying mirror energy differences (MEDs) in the function of angular momentum I. Methods: To compute MEDs we use a DFT-rooted no core configuration interaction model. This post-mean-field method restores rotational symmetry and takes into account configuration mixing within a space that includes relevant (multi)particle-(multi)hole Slater determinants. Results: We applied the model to f(7/2)-shell mirror pairs of A = 43, 45, 47, and 49 focusing on MEDs in the low-spin part (below band crossing), which allowed us to limit the model space to seniority one and three (one broken pair) configurations. Conclusions: We demonstrate that, for spins I <= 15/2 being the subject of the present study, our model reproduces well experimental MEDs, which vary strongly in the function of I and A. The quality of the model's predictions forMEDs is comparable to the nuclear shell-model results by Bentley et al.

Automated summary

The study aims to test mirror energy differences using charge-dependent density functional theory and DFT-rooted no core configuration interaction model. The results demonstrate that the model can accurately reproduce experimental mirror energy differences that vary significantly with different spins and masses.