Charge symmetry breaking effects of $\omega$-$\rho^0$ mixing in relativistic mean-field model

Abstract

We present a relativistic mean-field model that incorporates charge symmetry breaking (CSB) of nuclear force via $ \omega $-$ \rho^0 $ meson mixing, along with corrections to the electromagnetic interaction including the nucleon form factors, first-order vacuum polarization, and Coulomb exchange and pairing terms. The model parameters are refitted using the mass differences of $ T = 1/2 $ mirror nuclei and ground-state properties of magic nuclei, yielding DD-ME-CSB parameter set. The DD-ME-CSB parameter set reproduces the mass differences of mirror nuclei reasonably well up to $ T = 2 $, demonstrating the importance of $ \omega $-$ \rho^0 $ mixing. A connection of the present model to a Skyrme-type CSB interaction is also established through a gradient expansion of the energy density functional.