Hanbury-Brown-Twiss(HBT) correlations for charged pions in central Au+Au collisions at √SNN=2.4-7.7 GeV(corresponding to beam kinetic energies in the fixed target frame from Elab=1.23 to 30 GeV/nucleon) are calculate...Hanbury-Brown-Twiss(HBT) correlations for charged pions in central Au+Au collisions at √SNN=2.4-7.7 GeV(corresponding to beam kinetic energies in the fixed target frame from Elab=1.23 to 30 GeV/nucleon) are calculated using the ultra-relativistic quantum molecular dynamics model with different equations of state(EoSs).The effects of a phase transition at high baryon densities are clearly observed in the explored HBT parameters.The results show that the available data on the HBT radii,RO/RSand R^(2)_(O)-R^(2)_(S),in the investigated energy region favor a relatively stiff EoS at low beam energies,which then turns into a soft EoS at high collision energies consistent with astrophysical constraints on the high-density EoS of quantum chromodynamics(QCD).The specific effects of two different phase transition scenarios on RO/RSand R^(2)_(O)-R^(2)_(S)are investigated.A phase transition with a significant softening of the EoS below four times the nuclear saturation density can be excluded using HBT data.Our results highlight that the pion’s RO/RSand R^(2)_(O)-R^(2)_(S)are sensitive to the stiffness of the EoS and can be used to constrain and understand the QCD EoS in a high baryon density region.展开更多
Based on the updated UrQMD transport model,the effect of the symmetry potential energy on the two-nucleon HBT correlation is investigated with the help of the coalescence program for constructing clusters,and the CRAB...Based on the updated UrQMD transport model,the effect of the symmetry potential energy on the two-nucleon HBT correlation is investigated with the help of the coalescence program for constructing clusters,and the CRAB analyzing program of the two-particle HBT correlation.An obvious nonlinear dependence of the neutron-proton(or neutron-neutron) HBT correlation function(Cnp,nn) at small relative momenta on the stiffness factor γ of the symmetry potential energy is found:when γ 0.8,Cnp,nn increases rapidly with increasing γ,while it starts to saturate if γ 0.8.It is also found that both the symmetry potential energy at low densities and the conditions of constructing clusters at the late stage of the whole process influence the two-nucleon HBT correlation with the same power.展开更多
Making use of the maximum entropy method, we study the most probable source function in heavy ion collisions. An anisotropic Gaussian source is deduced by simply assuming that the particles are emitted within a finite...Making use of the maximum entropy method, we study the most probable source function in heavy ion collisions. An anisotropic Gaussian source is deduced by simply assuming that the particles are emitted within a finite proper-time. The general relations between the most probable source function and the minimal assumptions are discussed, which are instructive in constructing a self-consistent source function from observed Hanbury-Brown/Twiss（HBT） correlations.展开更多
The compact spectrometer for heavy ion experiment(CSHINE)is under construction for the study of isospin chronology via the Hanbury Brown–Twiss(HBT)particle correlation function and the nuclear equation of state of as...The compact spectrometer for heavy ion experiment(CSHINE)is under construction for the study of isospin chronology via the Hanbury Brown–Twiss(HBT)particle correlation function and the nuclear equation of state of asymmetrical nuclear matter.The CSHINE consists of silicon strip detector(SSD)telescopes and large-area parallel-plate avalanche counters,which measure the light charged particles and fission fragments,respectively.In phase I,two SSD telescopes were used to observe 30 MeV/u 40Ar?197Au reactions.The results presented here demonstrate that hydrogen and helium were observed with high isotopic resolution,and the HBT correlation functions of light charged particles could be constructed from the obtained data.展开更多
We give the formulas of two-pion Hanbury-Brown-Twiss （HBT） correlation function for a partially coherent evolution pion-emitting source, using quantum probability amplitudes in a path-integral formalism. The multipl...We give the formulas of two-pion Hanbury-Brown-Twiss （HBT） correlation function for a partially coherent evolution pion-emitting source, using quantum probability amplitudes in a path-integral formalism. The multiple scattering of the particles in the source is taken into consideration based on Glauber scattering theory. Two-pion interferometry with effects of the multiple scattering and source collective expansion is examined for a partially coherent source of hadronic gas with a finite baryon density and evolving hydrodynamically. We do not find observable effect of either the multiple scattering or the source collective expansion on HBT chaotic parameter.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11875125,and 12075085)financial support from China Scholarship Council(Grant No.202106180053)Samson AG for funding。
文摘Hanbury-Brown-Twiss(HBT) correlations for charged pions in central Au+Au collisions at √SNN=2.4-7.7 GeV(corresponding to beam kinetic energies in the fixed target frame from Elab=1.23 to 30 GeV/nucleon) are calculated using the ultra-relativistic quantum molecular dynamics model with different equations of state(EoSs).The effects of a phase transition at high baryon densities are clearly observed in the explored HBT parameters.The results show that the available data on the HBT radii,RO/RSand R^(2)_(O)-R^(2)_(S),in the investigated energy region favor a relatively stiff EoS at low beam energies,which then turns into a soft EoS at high collision energies consistent with astrophysical constraints on the high-density EoS of quantum chromodynamics(QCD).The specific effects of two different phase transition scenarios on RO/RSand R^(2)_(O)-R^(2)_(S)are investigated.A phase transition with a significant softening of the EoS below four times the nuclear saturation density can be excluded using HBT data.Our results highlight that the pion’s RO/RSand R^(2)_(O)-R^(2)_(S)are sensitive to the stiffness of the EoS and can be used to constrain and understand the QCD EoS in a high baryon density region.
基金Supported by the Frankfurt Center for Scientific Computing (CSC),the Key Project of the Ministry of Education of China (Grant No.209053)the National Natural Science Foundation of China (Grant No.10675046)
文摘Based on the updated UrQMD transport model,the effect of the symmetry potential energy on the two-nucleon HBT correlation is investigated with the help of the coalescence program for constructing clusters,and the CRAB analyzing program of the two-particle HBT correlation.An obvious nonlinear dependence of the neutron-proton(or neutron-neutron) HBT correlation function(Cnp,nn) at small relative momenta on the stiffness factor γ of the symmetry potential energy is found:when γ 0.8,Cnp,nn increases rapidly with increasing γ,while it starts to saturate if γ 0.8.It is also found that both the symmetry potential energy at low densities and the conditions of constructing clusters at the late stage of the whole process influence the two-nucleon HBT correlation with the same power.
基金Supported by National Natural Science Foundation of China (10835005, 90503001, 90103019)
文摘Making use of the maximum entropy method, we study the most probable source function in heavy ion collisions. An anisotropic Gaussian source is deduced by simply assuming that the particles are emitted within a finite proper-time. The general relations between the most probable source function and the minimal assumptions are discussed, which are instructive in constructing a self-consistent source function from observed Hanbury-Brown/Twiss（HBT） correlations.
基金This work was supported by the National Natural Science Foundation of China(Nos.11875174 and 11961131010)。
文摘The compact spectrometer for heavy ion experiment(CSHINE)is under construction for the study of isospin chronology via the Hanbury Brown–Twiss(HBT)particle correlation function and the nuclear equation of state of asymmetrical nuclear matter.The CSHINE consists of silicon strip detector(SSD)telescopes and large-area parallel-plate avalanche counters,which measure the light charged particles and fission fragments,respectively.In phase I,two SSD telescopes were used to observe 30 MeV/u 40Ar?197Au reactions.The results presented here demonstrate that hydrogen and helium were observed with high isotopic resolution,and the HBT correlation functions of light charged particles could be constructed from the obtained data.
基金Supported by National Natural Science Foundation of China (10575024)
文摘We give the formulas of two-pion Hanbury-Brown-Twiss （HBT） correlation function for a partially coherent evolution pion-emitting source, using quantum probability amplitudes in a path-integral formalism. The multiple scattering of the particles in the source is taken into consideration based on Glauber scattering theory. Two-pion interferometry with effects of the multiple scattering and source collective expansion is examined for a partially coherent source of hadronic gas with a finite baryon density and evolving hydrodynamically. We do not find observable effect of either the multiple scattering or the source collective expansion on HBT chaotic parameter.
