document: We investigate the density behavior of the symmetry energy with respect to isospin equilibration in the combined systems Ru(Zr)+Zr(Ru) at relativistic energies of 0.4 and 1.528A GeV. The study is performed within a relativistic framework and the contribution of the iso-vector, scalar δ field to the symmetry energy and the isospin dynamics is particularly explored. We find that the isospin mixing depends on the symmetry energy and a stiffer behavior leads to more transparency. The results are also nicely sensitive to the “fine structure” of the symmetry energy, i.e., to the covariant properties of the isovector meson fields.The isospin tracing appears much less dependent on the in medium neutron–proton cross sections (σnp) and this makes such observable very peculiar for the study of the isovector part of the nuclear equation of state.Within such a framework, comparisons with experiments support the introduction of the δ meson in the description of the iso-vector equation of state.
extractive_keyphrases: combined systems comparisons with experiments investigate the density behavior of the symmetry energy with respect to isospin equilibration isospin mixing medium neutron–proton cross sections relativistic energies relativistic framework scalar δ field to the symmetry energy and the isospin dynamics is particularly explored study δ meson σnp
abstractive_keyphrases: contribution of the iso-vector introduction of the δ meson in the description of the iso-vector equation of state isovector meson fields ru(zr)+zr(ru) study of the isovector part of the nuclear equation of state