Pion properties at finite temperature, finite isospin and baryon chemical potentials are investigated within the SU（2） NJL model. In the mean field approximation for quarks and random phase approximation fpr mesons,...Pion properties at finite temperature, finite isospin and baryon chemical potentials are investigated within the SU（2） NJL model. In the mean field approximation for quarks and random phase approximation fpr mesons, we calculate the pion mass, the decay constant and the phase diagram with different quark masses for the u quark and d quark, related to QCD corrections, for the first time. Our results show an asymmetry between μI 〈 0 and μI 〉0 in the phase diagram, and different values for the charged pion mass（or decay constant） and neutral pion mass（or decay constant） at finite temperature and finite isospin chemical potential. This is caused by the effect of isospin symmetry breaking, which is from different quark masses.展开更多
The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is found.We al...The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is found.We also explore some properties of the skyrmion as function of i.e.,the isoscalar rms radius and the isoscalar magnetic rms radius.Finally,considering the finite temperature effect on the skyrmion mass,we obtain a critical temperature T_c,using the profile function of the skyrmion,above which the skyrmion mass does not have a minimum,which can be interpreted as the occurrence of the deconfinement phase transition.展开更多
We study the phase transition between the pion condensed phase and normal phase,as well as chiral phase transition in a two flavor(Nf=2)IR-improved soft-wall AdS/QCD model at finite isospin chemical potentialμI and t...We study the phase transition between the pion condensed phase and normal phase,as well as chiral phase transition in a two flavor(Nf=2)IR-improved soft-wall AdS/QCD model at finite isospin chemical potentialμI and temperature T.By self-consistently solving the equations of motion,we obtain the phase diagram in the plane ofμI and T.The pion condensation appears together with a massless Nambu-Goldstone boson mπ1(Tc,μcI)=0,which is very likely to be a second-order phase transition with mean-field critical exponents in the smallμI region.When T=0,the critical isospin chemical potential approximates to vacuum pion massμcI≈m0.The pion condensed phase exists in an arched area,and the boundary of the chiral crossover intersects the pion condensed phase at a tri-critical point.Qualitatively,the results are in good agreement with previous studies on lattice simulations and model calculations.展开更多
The symmetry energy at the time of the production of intermediate mass fragments(IMFs) is studied using experimentally observed IMF multiplicities combined with quantum statistical model calculations(QSM of Hahn and S...The symmetry energy at the time of the production of intermediate mass fragments(IMFs) is studied using experimentally observed IMF multiplicities combined with quantum statistical model calculations(QSM of Hahn and St cker).The ratios of difference in chemical potentials between neutrons and protons relative to the temperature,(μn-μp)/T,and the double ratio temperature,T,were extracted experimentally in the reactions of64,70Zn,64Ni+58,64Ni,112,124Sn,197Au,232Th at 40A MeV.The extracted(μn-μp)/TTscales linearly with δNN,where δNN is the asymmetry parameter,(N-Z)/A,of the emitting source and(μn-μp)/T=(11.1 1.4)δNN0.21 was derived.The experimentally extracted(μn-μp)/T and the double ratio temperatures are compared with those from the QSM calculations.The temperatures-,T,and densities,ρ,extracted from the(μn-μp)/T values agreed with those from the double ratio thermometer which used the yield ratios of d,t,h and α particles.However the two analyses of the differential chemical potential analysis and the initial temperature analysis end up almost identical relation between T and ρ.T=5.25±0.75 MeV is evaluated from the(μn-μp)/Tanalysis,but no density determination was possible.From the extracted T value,the symmetry energy coefficient Esym =14.6±3.5 MeV is determined for the emitting source of T=5.25±0.75 MeV.展开更多
We improve the isospin dependent quantum molecular dynamical model by including isospin effects in the Skyrme potential and the momentum dependent interaction to obtain an isospin dependent Skyrme potential and an iso...We improve the isospin dependent quantum molecular dynamical model by including isospin effects in the Skyrme potential and the momentum dependent interaction to obtain an isospin dependent Skyrme potential and an isospin dependent momentum interaction. We investigate the isospin effects of Skyrme potential and momentum dependent interaction on the isospin fractionation ratio and the dynamical mechanism in intermediate energy heavy ion collisions. It is found that the isospin dependent Skyrme potential and the isospin dependent momentum interaction produce some important isospin effects in the isospin fractionation ratio.展开更多
We investigate the neutron and proton single particle （s.p.） potentials of asymmetric nuclear matter and their isospin dependence in various spin-isospin ST channels within the framework of the BruecknerHartree-Fock...We investigate the neutron and proton single particle （s.p.） potentials of asymmetric nuclear matter and their isospin dependence in various spin-isospin ST channels within the framework of the BruecknerHartree-Fock approach. It is shown that in symmetric nuclear matter, the s.p. potentials in both the isospinsinglet T = 0 channel and isospin-triplet T = 1 channel are essentially attractive, and the magnitudes in the two different channels are roughly the same. In neutron-rich nuclear matter, the isospin-splitting of the proton and neutron s.p. potentials turns out to be mainly determined by the isospin-singlet T = 0 channel contribution which becomes more attractive for the proton and more repulsive for the neutron at higher asymmetries.展开更多
The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of isospin-dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive ...The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of isospin-dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive to the form of the density dependence of the symmetry potential energy but also its strength determined by the symmetry energy coefficient. The uncertainties about the symmetry energy coefficient influence the accuracy of probing the density dependence of the symmetry energy by means of the N/Z ratio of free nucleons of neutron-rich nuclei.展开更多
The relation between the vector-isoscalar and vector-isovector interactions in the two-flavor Nambu-JonaLasinio(NJL) model is investigated under the different constraints from QCD. We demonstrate that the flavormixing...The relation between the vector-isoscalar and vector-isovector interactions in the two-flavor Nambu-JonaLasinio(NJL) model is investigated under the different constraints from QCD. We demonstrate that the flavormixing can be induced by the mismatched vector-isoscalar and vector-isovector interactions at finite baryon chemical potential μ and isospin chemical potential μI. The effect of this non-anomaly flavor-mixing on the possible separate chiral transitions at nonzero μIis studied under the assumption of the effective restoration of U(1)Asymmetry. We find that for the weak isospin asymmetry, the two separate phase boundaries found previously can be converted into one only if the vector-isovector coupling gv vis significantly stronger than the vector-isoscalar one gs vwithout the axial anomaly.展开更多
基金Supported by National Natural Science Foundation of China(11175088,11475085,11535005,11690030)the Fundamental Research Funds for the Central Universities(020414380074)
文摘Pion properties at finite temperature, finite isospin and baryon chemical potentials are investigated within the SU（2） NJL model. In the mean field approximation for quarks and random phase approximation fpr mesons, we calculate the pion mass, the decay constant and the phase diagram with different quark masses for the u quark and d quark, related to QCD corrections, for the first time. Our results show an asymmetry between μI 〈 0 and μI 〉0 in the phase diagram, and different values for the charged pion mass（or decay constant） and neutral pion mass（or decay constant） at finite temperature and finite isospin chemical potential. This is caused by the effect of isospin symmetry breaking, which is from different quark masses.
基金Supported in part by Natural Science Foundation of China(NSFC)(11805097,11535005,11690030)the Jiangsu Provincial Natural Science Foundation of China(BK20180323)
文摘The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is found.We also explore some properties of the skyrmion as function of i.e.,the isoscalar rms radius and the isoscalar magnetic rms radius.Finally,considering the finite temperature effect on the skyrmion mass,we obtain a critical temperature T_c,using the profile function of the skyrmion,above which the skyrmion mass does not have a minimum,which can be interpreted as the occurrence of the deconfinement phase transition.
基金Supported by the National Natural Science Foundation of China(11405074)Supported by the National Natural Science Foundation of China(11805084)+1 种基金the PhD Start-up Fund of Natural Science Foundation of Guangdong Province(2018030310457)Guangdong Pearl River Talents Plan(2017GC010480)。
文摘We study the phase transition between the pion condensed phase and normal phase,as well as chiral phase transition in a two flavor(Nf=2)IR-improved soft-wall AdS/QCD model at finite isospin chemical potentialμI and temperature T.By self-consistently solving the equations of motion,we obtain the phase diagram in the plane ofμI and T.The pion condensation appears together with a massless Nambu-Goldstone boson mπ1(Tc,μcI)=0,which is very likely to be a second-order phase transition with mean-field critical exponents in the smallμI region.When T=0,the critical isospin chemical potential approximates to vacuum pion massμcI≈m0.The pion condensed phase exists in an arched area,and the boundary of the chiral crossover intersects the pion condensed phase at a tri-critical point.Qualitatively,the results are in good agreement with previous studies on lattice simulations and model calculations.
基金Supported by National Natural Science Foundation of China(NSFC) Projects (No.11075189)"100 Persons Project(Nos.0910020BR0 and Y010110BR0)"+2 种基金"ADS project 302"of the Chinese Academy of Sciences(No.Y103010ADS)supported by U.S.Department of Energy(Grant No.DE-FG03-93ER40773)Robert A.Welch Foundation(Grant A0330)
文摘The symmetry energy at the time of the production of intermediate mass fragments(IMFs) is studied using experimentally observed IMF multiplicities combined with quantum statistical model calculations(QSM of Hahn and St cker).The ratios of difference in chemical potentials between neutrons and protons relative to the temperature,(μn-μp)/T,and the double ratio temperature,T,were extracted experimentally in the reactions of64,70Zn,64Ni+58,64Ni,112,124Sn,197Au,232Th at 40A MeV.The extracted(μn-μp)/TTscales linearly with δNN,where δNN is the asymmetry parameter,(N-Z)/A,of the emitting source and(μn-μp)/T=(11.1 1.4)δNN0.21 was derived.The experimentally extracted(μn-μp)/T and the double ratio temperatures are compared with those from the QSM calculations.The temperatures-,T,and densities,ρ,extracted from the(μn-μp)/T values agreed with those from the double ratio thermometer which used the yield ratios of d,t,h and α particles.However the two analyses of the differential chemical potential analysis and the initial temperature analysis end up almost identical relation between T and ρ.T=5.25±0.75 MeV is evaluated from the(μn-μp)/Tanalysis,but no density determination was possible.From the extracted T value,the symmetry energy coefficient Esym =14.6±3.5 MeV is determined for the emitting source of T=5.25±0.75 MeV.
基金Supported by National Natural Science Foundation of China(10435080,10447006,10575075)CAS Knowledge Innovation Project(KJCX2-SW-N02)+2 种基金Major State Basic Research Development Program in China(G2000077400)the Scientific Research Funds for the Doctor,University of Shanghai for Science and Technologythe Science and Technological Fund of Shanghai Municipal Education Commission for Selecting and Cultivating Excellent University Young Teachers
文摘We improve the isospin dependent quantum molecular dynamical model by including isospin effects in the Skyrme potential and the momentum dependent interaction to obtain an isospin dependent Skyrme potential and an isospin dependent momentum interaction. We investigate the isospin effects of Skyrme potential and momentum dependent interaction on the isospin fractionation ratio and the dynamical mechanism in intermediate energy heavy ion collisions. It is found that the isospin dependent Skyrme potential and the isospin dependent momentum interaction produce some important isospin effects in the isospin fractionation ratio.
基金Supported by National Natural Science Foundation of China (11175219, 10875151, 10740420550)Major State Basic Research Developing Program of China (2007CB815004)+2 种基金Knowledge Innovation Project of Chinese Academy of Sciences (KJCX2-EW-N01)Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (2009J2-26)CAS/SAFEA International Partnership Program for Creative Research Teams (CXTD-J2005-1)
文摘We investigate the neutron and proton single particle （s.p.） potentials of asymmetric nuclear matter and their isospin dependence in various spin-isospin ST channels within the framework of the BruecknerHartree-Fock approach. It is shown that in symmetric nuclear matter, the s.p. potentials in both the isospinsinglet T = 0 channel and isospin-triplet T = 1 channel are essentially attractive, and the magnitudes in the two different channels are roughly the same. In neutron-rich nuclear matter, the isospin-splitting of the proton and neutron s.p. potentials turns out to be mainly determined by the isospin-singlet T = 0 channel contribution which becomes more attractive for the proton and more repulsive for the neutron at higher asymmetries.
基金The project supported by National Natural Science Foundation of China under Grant Nos.10175093 and 10235030+4 种基金the Science Foundation of Chinese Nuclear Industry and the State Key Basic Research Development Program under Contract No.G20000774the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant No.KJCX2-SW-N02the CASK.C.Wong Post-doctors Research Award Fund
文摘The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of isospin-dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive to the form of the density dependence of the symmetry potential energy but also its strength determined by the symmetry energy coefficient. The uncertainties about the symmetry energy coefficient influence the accuracy of probing the density dependence of the symmetry energy by means of the N/Z ratio of free nucleons of neutron-rich nuclei.
基金Supported by the National Natural Science Foundation of China(No.11275069)
文摘The relation between the vector-isoscalar and vector-isovector interactions in the two-flavor Nambu-JonaLasinio(NJL) model is investigated under the different constraints from QCD. We demonstrate that the flavormixing can be induced by the mismatched vector-isoscalar and vector-isovector interactions at finite baryon chemical potential μ and isospin chemical potential μI. The effect of this non-anomaly flavor-mixing on the possible separate chiral transitions at nonzero μIis studied under the assumption of the effective restoration of U(1)Asymmetry. We find that for the weak isospin asymmetry, the two separate phase boundaries found previously can be converted into one only if the vector-isovector coupling gv vis significantly stronger than the vector-isoscalar one gs vwithout the axial anomaly.
