The quark meson coupling model is used to investigate the correlation between thenuclear incompressibility K and the third order derivitive K′ of the nuclear matter saturationcurve,the temperature and entropy depende...The quark meson coupling model is used to investigate the correlation between thenuclear incompressibility K and the third order derivitive K′ of the nuclear matter saturationcurve,the temperature and entropy dependence of the nuclear展开更多
K-condensation and quark deconfinement phase transitions in neutron stars are investigated.We use themodified quark-meson coupling model for hadronic phase and the MIT bag model for quark phase.With the equationof sta...K-condensation and quark deconfinement phase transitions in neutron stars are investigated.We use themodified quark-meson coupling model for hadronic phase and the MIT bag model for quark phase.With the equationof state (EOS) solved self-consistently,we discuss the properties of neutron stars.We find that the EOS of pure hadronmatter with condensed K^- phase should be ruled out by the redshift for star EX00748-676,while EOS containingunpaired quark matter phase with B^(1/4) being about 180 MeV could be consistent with both this observation and thebest measured mass of star PSR 1913+16.But if the recent inferred massive star among Terzan 5 with M>1.68M_⊙is confirmed,all the present EOSes with condensed phase and decor,fined phase would be ruled out.展开更多
We investigate the chiral phase structure of quark matter with spheroidal momentum-space anisotropy specified by one anisotropy parameter ξ in the 2+1 flavor quark-meson model.We find that the chiral phase diagram an...We investigate the chiral phase structure of quark matter with spheroidal momentum-space anisotropy specified by one anisotropy parameter ξ in the 2+1 flavor quark-meson model.We find that the chiral phase diagram and the location of the critical endpoint(CEP) are significantly affected by the value of ξ.With an increase inξ,the CEP is shifted to lower temperatures and higher quark chemical potentials.In addition,the temperature of the CEP is more sensitive to the anisotropy parameter than the corresponding quark chemical potential,which is the opposite to that from the finite system volume effect.The effects of the momentum anisotropy on the thermodynamic properties and scalar(pseudoscalar) meson masses are also studied at the vanishing quark chemical potential.The numerical results reveal that an increase in ξ can hinder the restoration of chiral symmetry.We also find that shear viscosity and electrical conductivity decrease as ξ increases.However,the bulk viscosity exhibits a significant nontrivial behavior with ξ in the entire temperature domain of interest.展开更多
In the present work,we used five different versions of the quark-meson coupling(QMC)model to compute astrophysical quantities related to the GW170817 event and the neutron star cooling process.Two of the models are ba...In the present work,we used five different versions of the quark-meson coupling(QMC)model to compute astrophysical quantities related to the GW170817 event and the neutron star cooling process.Two of the models are based on the original bag potential structure and three versions consider a harmonic oscillator potential to confine quarks.The bag-like models also incorporate the pasta phase used to describe the inner crust of neutron stars.With a simple method studied in the present work,we show that the pasta phase does not play a significant role.Moreover,the QMC model that satisfies the GW170817 constraints with the lowest slope of the symmetry energy exhibits a cooling profile compatible with observational data.展开更多
We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson model.The contribution of the fermionic vacuum loop in the effective thermodynamics...We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson model.The contribution of the fermionic vacuum loop in the effective thermodynamics potential and phase diagram,together with the location of the critical endpoint(CEP),is obtained in the temperature and chemical potential plane.For weak and strong first-order phase transitions,by taking the temperature as a variable,the critical bubble profiles,evolutions of the surface tension,and saddle-point action in the presence of a nucleation bubble are numerically calculated in detail when fixing the chemical potentials atμ=306 MeV andμ=309 MeV.Our results show that the system could be trapped in the metastable state for a long time as long as the temperature is between the metastable region characterized by the up and low spinodal lines.Moreover,the surface tension at criticality will rise to approximately 4 MeV/fm2 when the chemical potential is very high.Such a small surface tension value would favor a mixed phase in the cores of compact stars and may have an important implication in astrophysics.展开更多
基金The project supported in part by the National Natural Science Foundation of China and by the Chinese Academy of Sciences under Contract No.LWTZ-1298
文摘The quark meson coupling model is used to investigate the correlation between thenuclear incompressibility K and the third order derivitive K′ of the nuclear matter saturationcurve,the temperature and entropy dependence of the nuclear
基金National Natural Science Foundation of China under Grant Nos.10305001,10475002,and 10435080
文摘K-condensation and quark deconfinement phase transitions in neutron stars are investigated.We use themodified quark-meson coupling model for hadronic phase and the MIT bag model for quark phase.With the equationof state (EOS) solved self-consistently,we discuss the properties of neutron stars.We find that the EOS of pure hadronmatter with condensed K^- phase should be ruled out by the redshift for star EX00748-676,while EOS containingunpaired quark matter phase with B^(1/4) being about 180 MeV could be consistent with both this observation and thebest measured mass of star PSR 1913+16.But if the recent inferred massive star among Terzan 5 with M>1.68M_⊙is confirmed,all the present EOSes with condensed phase and decor,fined phase would be ruled out.
基金Supported by the National Natural Science Foundation of China(11935007)the Fundamental Research Funds for the Central Universities(2020CXZZ107).
文摘We investigate the chiral phase structure of quark matter with spheroidal momentum-space anisotropy specified by one anisotropy parameter ξ in the 2+1 flavor quark-meson model.We find that the chiral phase diagram and the location of the critical endpoint(CEP) are significantly affected by the value of ξ.With an increase inξ,the CEP is shifted to lower temperatures and higher quark chemical potentials.In addition,the temperature of the CEP is more sensitive to the anisotropy parameter than the corresponding quark chemical potential,which is the opposite to that from the finite system volume effect.The effects of the momentum anisotropy on the thermodynamic properties and scalar(pseudoscalar) meson masses are also studied at the vanishing quark chemical potential.The numerical results reveal that an increase in ξ can hinder the restoration of chiral symmetry.We also find that shear viscosity and electrical conductivity decrease as ξ increases.However,the bulk viscosity exhibits a significant nontrivial behavior with ξ in the entire temperature domain of interest.
基金This work is a part of the projet INCT-FNA Proe.(464898/2014-5),was partially supprted by CNPq(Brazil)(301155.2017-8)(D.P.M.),310242/2017-7,406958/2018-1(O.L),308486/2015-3(T.F.),43369/2018-3(M.D.),by Capes-PNPD program(C.V.F),and by Fundacio de Amparo a Pesquisa do Estado de Sio Paulo(FAPESP)under the thematic projescts 2013/26258-4(OL,TF)and 2017/05660-0(OL,M.D.T.E.).R.N.also acknowledges that this project was parly funded by FAPERJ,under grant E-26/203.2992017.M.B.acknowledge the support from FAPESP Project No.2017/05660-0,and FOSTECT Project No.FOSTECT.2019B.04.PDS acknow ledges support from the UK STFC under projeet number ST/P005314/1。
文摘In the present work,we used five different versions of the quark-meson coupling(QMC)model to compute astrophysical quantities related to the GW170817 event and the neutron star cooling process.Two of the models are based on the original bag potential structure and three versions consider a harmonic oscillator potential to confine quarks.The bag-like models also incorporate the pasta phase used to describe the inner crust of neutron stars.With a simple method studied in the present work,we show that the pasta phase does not play a significant role.Moreover,the QMC model that satisfies the GW170817 constraints with the lowest slope of the symmetry energy exhibits a cooling profile compatible with observational data.
基金Supported in part by the National Natural Science Foundation of China(NSFC)(11675048)。
文摘We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson model.The contribution of the fermionic vacuum loop in the effective thermodynamics potential and phase diagram,together with the location of the critical endpoint(CEP),is obtained in the temperature and chemical potential plane.For weak and strong first-order phase transitions,by taking the temperature as a variable,the critical bubble profiles,evolutions of the surface tension,and saddle-point action in the presence of a nucleation bubble are numerically calculated in detail when fixing the chemical potentials atμ=306 MeV andμ=309 MeV.Our results show that the system could be trapped in the metastable state for a long time as long as the temperature is between the metastable region characterized by the up and low spinodal lines.Moreover,the surface tension at criticality will rise to approximately 4 MeV/fm2 when the chemical potential is very high.Such a small surface tension value would favor a mixed phase in the cores of compact stars and may have an important implication in astrophysics.
