Isovector-channel role of relativistic mean field models in the neutrino mean free path

An improvement in the treatment of the isovector channel of relativistic mean field (RMF) models based on effective field theory (E-RMF) is suggested, by adding an isovector scalar ({delta}) meson and using a similar procedure to the one used by Horowitz and Piekarewicz to adjust the isovector-vector channel in order to achieve a softer density dependent symmetry energy of the nuclear matter at high density. Their effects on the equation of state (EOS) at high density and on the neutrino mean free path (NMFP) in neutron stars are discussed.