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.

Comments: 16 pages, 6 figures