Circumstantial evidence for a soft nuclear symmetry energy at suprasaturation densities.
نویسندگان
چکیده
Within an isospin- and momentum-dependent hadronic transport model, it is shown that the recent FOPI data on the pi;{-}/pi;{+} ratio in central heavy-ion collisions at SIS/GSI energies [Willy Reisdorf, Nucl. Phys. A 781, 459 (2007)10.1016/j.nuclphysa.2006.10.085] provide circumstantial evidence suggesting a rather soft nuclear symmetry energy E_{sym}(rho) at rho> or =2rho_{0} compared to the Akmal-Pandharipande-Ravenhall prediction. Some astrophysical implications and the need for further experimental confirmations are discussed.
منابع مشابه
Supersoft symmetry energy encountering non-Newtonian gravity in neutron stars.
Considering the non-Newtonian gravity proposed in grand unification theories, we show that the stability and observed global properties of neutron stars cannot rule out the supersoft nuclear symmetry energies at suprasaturation densities. The degree of possible violation of the inverse-square law of gravity in neutron stars is estimated using an equation of state of neutron-rich nuclear matter ...
متن کاملProbing the Symmetry Energy with Heavy Ions
Constraints on the EoS for symmetric matter (equal neutron and proton numbers) at suprasaturation densities have been extracted from energetic collisions of heavy ions. Collisions of neutron-deficient and neutron-rich heavy ions now provide initial constraints on the EoS of neutronrich matter at sub-saturation densities. Comparisons are made to other available constraints.
متن کاملSymmetry energy at subnuclear densities and nuclei in a neutron-star crust
We examine how the properties of inhomogeneous nuclear matter at subnuclear densities depend on the density dependence of the symmetry energy. We focus on a parameter that characterizes the density dependence of the symmetry energy S(n) at about nuclear density n0. It is the density symmetry coefficient L = 3n0(dS/dn)n=n0 . From the saturation properties of stable nuclei, we find that the usual...
متن کاملKaon Condensation in Neutron Stars and High Density Behaviour of Nuclear Symmetry
We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaonnucleon couplings at any density. There exists a threshold coupling above which the kaon condensate forms at densi...
متن کاملEquation of state of isospin-asymmetric nuclear matter in relativistic mean-field models with chiral limits
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 102 6 شماره
صفحات -
تاریخ انتشار 2009