Symmetry Energy with the Non-nucleonic Constituents in Nuclear Matter

Key words: 
• symmetry energy /
• hyperon /
• quark degrees of freedom /
• relativistic mean- eld model

Abstract: While the nuclear symmetry energy is usually studied in nite nuclei and nucleonic matter,we study the symmetry energy in relativistic mean- eld models with the inclusion of the hyperon and quark degrees of freedom at high densities. Apparent softening of the symmetry energy with the inclusion of hyperon and quark degrees of freedom is found and demonstrated in the relativistic mean-eld model. This softening would have associations with the symmetry energy extraction which needs detailed discriminations in dense matter with the admixture of new degrees of freedom created by heavy-ion collisions.