Equation of state of isospin-asymmetric nuclear matter in relativistic mean-field models with chiral limits

• Published in: Physics letters. B Vol. 653; no. 2; pp. 184 - 189
• Main Authors: Jiang, Wei-Zhou, Li, Bao-An, Chen, Lie-Wen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.09.2007; Elsevier Science
• Subjects: Chiral limits; Equation of state; Exact sciences and technology; Nuclear matter; Nuclear physics; Physics; Relativistic mean-field models; Symmetry energy; The physics of elementary particles and fields; Symmetry energy; 21.65.+f; Relativistic mean-field models; 11.30.Rd; 26.60.+c; Nuclear matter; Chiral limits; Equation of state; Mean field approximation; Neutron stars; Lagrangian; Coupling constants; High density; Saturation; Nuclear isospin; Hadrons; Heavy ion reactions; Equations of state; Stellar mass; Chiral symmetry; Models; Diffusion
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2007.08.004

Using in-medium hadron properties according to the Brown–Rho scaling due to the chiral symmetry restoration at high densities and considering naturalness of the coupling constants, we have newly constructed several relativistic mean-field Lagrangians with chiral limits. The model parameters are adjusted such that the symmetric part of the resulting equation of state at supra-normal densities is consistent with that required by the collective flow data from high energy heavy-ion reactions, while the resulting density dependence of the symmetry energy at sub-saturation densities agrees with that extracted from the recent isospin diffusion data from intermediate energy heavy-ion reactions. The resulting equations of state have the special feature of being soft at intermediate densities but stiff at high densities naturally. With these constrained equations of state, it is found that the radius of a 1.4 M ⊙ canonical neutron star is in the range of 11.9   km ⩽ R ⩽ 13.1   km , and the maximum neutron star mass is around 2.0 M ⊙ close to the recent observations.