The asymmetric neutron stars are investigated in a relativistic effective model with vacuum fluctuations(VF) taken into account. Due to the VF effects, various properties of the neutron matter become ‘softened' c...The asymmetric neutron stars are investigated in a relativistic effective model with vacuum fluctuations(VF) taken into account. Due to the VF effects, various properties of the neutron matter become ‘softened' comparing to that obtained in the FSUGold model, and the maximum mass of the enpelT neutron stars is reduced from1.71 M to 1:35M.展开更多
We explore the mechanism of the isospin splitting of neutron and proton effective masses in neutronrich nuclear matter within the framework of the Brueckner-Hartree-Fock (BHF) approach. First we find that the neutron-...We explore the mechanism of the isospin splitting of neutron and proton effective masses in neutronrich nuclear matter within the framework of the Brueckner-Hartree-Fock (BHF) approach. First we find that the neutron-proton effective mass splitting in neutron-rich matter is dominated by the nonlocality of the microscopic s. p. potentials in spatial space,i. e.,by the isospin splitting of the k-mass shown in Fig.展开更多
Within the spin-dependent Brueckner-Hatree-Fock framework, the equation of state ( EOS ) of the spin-polarized neutron matter has been investigated by adopting the realistic nucleon-nucleon interaction AV18 supplement...Within the spin-dependent Brueckner-Hatree-Fock framework, the equation of state ( EOS ) of the spin-polarized neutron matter has been investigated by adopting the realistic nucleon-nucleon interaction AV18 supplemented with the microscopic three-body force ( TBF ) based on the meson-exchange current method. The related physical quantities such as spin-symmetry energy, magnetic susceptibility and the Landau param-展开更多
We study the influence of the model parameters on the phase transitions, the equation of state （EOS）, and the corresponding mass-radius relations in the interior of neutron stars. The numerical analysis shows that t...We study the influence of the model parameters on the phase transitions, the equation of state （EOS）, and the corresponding mass-radius relations in the interior of neutron stars. The numerical analysis shows that the coupling constants of hyperons have a slight influence on the phase transitions and EOS, but an obvious influence on the particle fractions, while the bag constant B and coupling constant g have an important influence on the phase transitions, the EOS, and the mass-radius relations. We find that both the bag constant B and coupling constant g play the same role in the description of the interactions between quarks of hybrid stars. The maximum mass calculated by using the bag constant determined with experimental data （ranging from 175 to 200 MeV） falls in the interval of 1.4 ～1.7 solar mass. The corresponding radius is between 9.3 and 12 km. These results are in agreement with observed values of neutron stars. The possibility of the existence of a third family is discussed. The detection of a third family may provide a signature for a phase transition inside neutron stars.展开更多
Extracting the equation of state(EOS) and symmetry energy of dense neutron-rich matter from astrophysical observations is a long-standing goal of nuclear astrophysics. To facilitate the realization of this goal, the f...Extracting the equation of state(EOS) and symmetry energy of dense neutron-rich matter from astrophysical observations is a long-standing goal of nuclear astrophysics. To facilitate the realization of this goal, the feasibility of using an explicitly isospin-dependent parametric EOS for neutron star matter was investigated recently in [1–3]. In this contribution, in addition to outlining the model framework and summarizing the most important findings from [1–3], we report a few new results regarding constraining parameters characterizing the highdensity behavior of nuclear symmetry energy. In particular,the constraints on the pressure of neutron star matter extracted from combining the X-ray observations of the neutron star radius, the minimum–maximum mass M=2:01 M_⊙, and causality condition agree very well with those extracted from analyzing the tidal deformability data by the LIGO ? Virgo Collaborations. The limitations of using the radius and/or tidal deformability of neutron stars to constrain the high-density nuclear symmetry energy are discussed.展开更多
The numerical results of the populations for the baryon octet in neutron star matter have been presented by solving a set transcendental equations in the framework of the relativistic mean field approximation. The inf...The numerical results of the populations for the baryon octet in neutron star matter have been presented by solving a set transcendental equations in the framework of the relativistic mean field approximation. The influence of the hyperon interactions on hyperon populations in neutron star matter is discussed. The results manifest that when the ratio of the hyperon-to-nucleon couplings increases, all hyperons appear towards low baryon density direction.展开更多
基金supported by National Natural Science Foundation of China (No. 11435005)the Major State Basic Research Development Program in China (No. 2014CB845402)
文摘The asymmetric neutron stars are investigated in a relativistic effective model with vacuum fluctuations(VF) taken into account. Due to the VF effects, various properties of the neutron matter become ‘softened' comparing to that obtained in the FSUGold model, and the maximum mass of the enpelT neutron stars is reduced from1.71 M to 1:35M.
文摘We explore the mechanism of the isospin splitting of neutron and proton effective masses in neutronrich nuclear matter within the framework of the Brueckner-Hartree-Fock (BHF) approach. First we find that the neutron-proton effective mass splitting in neutron-rich matter is dominated by the nonlocality of the microscopic s. p. potentials in spatial space,i. e.,by the isospin splitting of the k-mass shown in Fig.
文摘Within the spin-dependent Brueckner-Hatree-Fock framework, the equation of state ( EOS ) of the spin-polarized neutron matter has been investigated by adopting the realistic nucleon-nucleon interaction AV18 supplemented with the microscopic three-body force ( TBF ) based on the meson-exchange current method. The related physical quantities such as spin-symmetry energy, magnetic susceptibility and the Landau param-
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10047001 and 10275029, the State Key Basic Reserch Development Program under Grant No, G2000-0774-07, and the CAS Knowledge Innovation Project under Grant No. KJCX2-N11
文摘We study the influence of the model parameters on the phase transitions, the equation of state （EOS）, and the corresponding mass-radius relations in the interior of neutron stars. The numerical analysis shows that the coupling constants of hyperons have a slight influence on the phase transitions and EOS, but an obvious influence on the particle fractions, while the bag constant B and coupling constant g have an important influence on the phase transitions, the EOS, and the mass-radius relations. We find that both the bag constant B and coupling constant g play the same role in the description of the interactions between quarks of hybrid stars. The maximum mass calculated by using the bag constant determined with experimental data （ranging from 175 to 200 MeV） falls in the interval of 1.4 ～1.7 solar mass. The corresponding radius is between 9.3 and 12 km. These results are in agreement with observed values of neutron stars. The possibility of the existence of a third family is discussed. The detection of a third family may provide a signature for a phase transition inside neutron stars.
基金NBZ was supported in part by the China Scholarship Councilthe U.S.Department of Energy,Office of Science,under Award Number DE-SC0013702,the CUSTIPEN(China-U.S.Theory Institute for Physics with Exotic Nuclei)under the U.S.Department of Energy Grant No.DE-SC0009971the National Natural Science Foundation of China under Grant No.11320101004
文摘Extracting the equation of state(EOS) and symmetry energy of dense neutron-rich matter from astrophysical observations is a long-standing goal of nuclear astrophysics. To facilitate the realization of this goal, the feasibility of using an explicitly isospin-dependent parametric EOS for neutron star matter was investigated recently in [1–3]. In this contribution, in addition to outlining the model framework and summarizing the most important findings from [1–3], we report a few new results regarding constraining parameters characterizing the highdensity behavior of nuclear symmetry energy. In particular,the constraints on the pressure of neutron star matter extracted from combining the X-ray observations of the neutron star radius, the minimum–maximum mass M=2:01 M_⊙, and causality condition agree very well with those extracted from analyzing the tidal deformability data by the LIGO ? Virgo Collaborations. The limitations of using the radius and/or tidal deformability of neutron stars to constrain the high-density nuclear symmetry energy are discussed.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10047001 and 10275029+2 种基金the State Key Basic Research Development Program under Grant No.G2000-0774-07the CAS Knowledge Innovation Project under Contract No.KJCX2-SW-N02
文摘The numerical results of the populations for the baryon octet in neutron star matter have been presented by solving a set transcendental equations in the framework of the relativistic mean field approximation. The influence of the hyperon interactions on hyperon populations in neutron star matter is discussed. The results manifest that when the ratio of the hyperon-to-nucleon couplings increases, all hyperons appear towards low baryon density direction.
