Incompressibility of neutron-rich matter

Abstract

The saturation properties of neutron-rich matter are investigated in a relativistic mean-field formalism using two accurately calibrated models: NL3 and FSUGold. The saturation properties - density, binding energy per nucleon, and incompressibility coefficient - are calculated as a function of the neutron-proton asymmetry alpha=(N-Z)/A to all orders in alpha. Good agreement (at the 10% level or better) is found between these numerical calculations and analytic expansions that are given in terms of a handful of bulk parameters determined at saturation density. Using insights developed from the analytic approach and a general expression for the incompressibility coefficient of infinite neutron-rich matter, i.e., K0(alpha)=K0+Ktau*alpha^{2}+..., we construct a Hybrid model with values for K0 and Ktau as suggested by recent experimental findings. Whereas the Hybrid model provides a better description of the measured distribution of isoscalar monopole strength in the Sn-isotopes relative to both NL3 and FSUGold, it significantly underestimates the distribution of strength in 208Pb. Thus, we conclude that the incompressibility coefficient of neutron-rich matter remains an important open problem.

23 pages, 9 figures, and 4 tables (to appear in PRC)

References in corpus (8)

• Neutron-Rich Nuclei in Heaven and Earth
• The Giant Dipole Resonance as a quantitative constraint on the symmetry energy
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• Isospin-dependent properties of asymmetric nuclear matter in relativistic mean-field models
• Why is Tin so soft?
• Microscopic linear response calculations based on the Skyrme functional plus the pairing contribution
• Validating relativistic models of nuclear structure against theoretical, experimental, and observational constraints
• Density dependence of symmetry free energy of hot nuclei

Cited by in corpus (6)

• Higher-order effects on the incompressibility of isospin asymmetric nuclear matter
• Neutron skin thickness in droplet model with surface width dependence: indications of softness of the nuclear symmetry energy
• The role of superfluidity in nuclear incompressibilities
• A phenomenological equation of state for isospin asymmetric nuclear matter
• Role of nonlinear vector meson interactions in hyperon stars
• Symmetry coefficients and incompressibility of clusterized supernova matter