Energy Dependent Isospin Asymmetry in Mean-Field Dynamics

TL;DR

This paper investigates how energy-dependent isospin asymmetry affects mean-field nuclear models, revealing a soft symmetry energy at high densities and predicting proton-neutron mass splitting due to rho-meson effects.

Contribution

It introduces an energy-dependent isospin asymmetry framework within relativistic mean-field theory with non-linear derivative interactions, providing new insights into symmetry energy and nucleon selfenergies.

Findings

Soft symmetry energy at high baryon densities.

Energy dependence suppresses Lane optical potential.

Predicts rho-meson induced proton-neutron mass splitting.

Abstract

The Lagrangian density of relativistic mean-field (RMF) theory with non-linear derivative (NLD) interactions is applied to isospin asymmetric nuclear matter. We study the symmetry energy and the density and energy dependences of nucleon selfenergies. At high baryon densities a soft symmetry energy is obtained. The energy dependence of the isovector selfenergy suppresses the Lane-type optical potential with increasing energy and predicts a $\rho$-meson induced mass splitting between protons and neutrons in isospin asymmetric matter.