We investigate the particle-hole fluctuation correction to the specific heat of an ultracold Fermi gas at unitarity within the framework of the non-self-consistent T-matrix approximation in the normal phase. We find g...We investigate the particle-hole fluctuation correction to the specific heat of an ultracold Fermi gas at unitarity within the framework of the non-self-consistent T-matrix approximation in the normal phase. We find good agreement between our theoretical predictions and the experimental data measured by the MIT group, apart from discrepancies near the transition temperature. At high temperature, our calculated specific heat has the tendency to approach the specific heat of the Boltzmann gas.展开更多
It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to un...It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics （QCD）. Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson-Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudo- critical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region.展开更多
In this work, we calculate the equation of state（EoS） of quark gluon-plasma（QGP） using the CornwallJackiw-Tomboulis（CJT） effective action. We get the quark propagator by using the rank-1 separable model within t...In this work, we calculate the equation of state（EoS） of quark gluon-plasma（QGP） using the CornwallJackiw-Tomboulis（CJT） effective action. We get the quark propagator by using the rank-1 separable model within the framework of the Dyson-Schwinger equations（DSEs）. The results from CJT effective action are compared with lattice QCD data. We find that, when μ is small, our results generally fit the lattice QCD data when T〉T_c,but show deviations at and below T_c. It can be concluded that the EoS of CJT is reliable when T〉T_c. Then,by adopting the hydrodynamic code UVH2＋1, we compare the CJT results of the multiplicity and elliptic flow v2 with the PHENIX data and the results from the original EoS in UVH2＋1. While the CJT results of multiplicities generally match the original UVH2＋1 results and fit the experimental data, the CJT results of v2 are slightly larger than the original UVH2＋1 results for centralities smaller than 40% and smaller than the original UVH2＋1 results for higher centralities.展开更多
We discuss the chiral phase transition of quantum chromodynamics （QCD） with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson-Schwinger equations, we focus particularly on the beh...We discuss the chiral phase transition of quantum chromodynamics （QCD） with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson-Schwinger equations, we focus particularly on the behavior of the widely accepted as well as interesting critical end point （CEP）, using a separable gluon propagator and a Gaussian gluon propagator. We find that there may be no CEP5 in the T-μ5 plane, and the phase transition in the T μ5 plane might be totally crossover. Our results have apparent consistency with the Lattice QCD calculation. On the other hand, our study may also provide some useful hints to some other studies related to μ5.展开更多
基金Supported by the Research Fund for Advanced Talents of Jiangsu University under Grant No 14JDG174the National Natural Science Foundation of China under Grants Nos 11447126,11275097,11475085 and 11535005the Natural Science Foundation of Jiangsu Province of China under Grant No BK20130078
文摘We investigate the particle-hole fluctuation correction to the specific heat of an ultracold Fermi gas at unitarity within the framework of the non-self-consistent T-matrix approximation in the normal phase. We find good agreement between our theoretical predictions and the experimental data measured by the MIT group, apart from discrepancies near the transition temperature. At high temperature, our calculated specific heat has the tendency to approach the specific heat of the Boltzmann gas.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11275097,11475085,11535005,and 11265017the Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No 1402006C+2 种基金the China Postdoctoral Science Foundation under Grant No 2015M571728the Natural Science Foundation of Jiangsu Province under Grant No BK20130078the Guizhou-Provincial Outstanding Youth Science and Technology Talent Cultivation Object Special Funds under Grant No QKHRZ(2013)28
文摘It is commonly accepted that the system undergoes a crossover at high temperature and low chemical potential beyond the chiral limit case, and the properties of the crossover region are important for researchers to understand the nature of strong interacting matters of quantum chromodynamics （QCD）. Since at present there is no exact order of parameters of the phase transitions beyond the chiral limit, QCD susceptibilities are widely used as indicators. In this work various susceptibilities are discussed in the framework of Dyson-Schwinger equations. The results show that different kinds of susceptibilities give the same critical end point, which is the bifurcation point of the crossover region and the first order phase transition line of QCD. Nevertheless, different pseudo- critical points are found in the temperature axis. We think that defining a critical band is more suitable in the crossover region.
基金Supported by National Natural Science Foundation of China(11447121,11475085,11535005,11690030)Fundamental Research Funds for the Central Universities(020414380074)+1 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(1501035B)Natural Science Foundation of Jiangsu Province(BK20130078,BK20130387)
文摘In this work, we calculate the equation of state（EoS） of quark gluon-plasma（QGP） using the CornwallJackiw-Tomboulis（CJT） effective action. We get the quark propagator by using the rank-1 separable model within the framework of the Dyson-Schwinger equations（DSEs）. The results from CJT effective action are compared with lattice QCD data. We find that, when μ is small, our results generally fit the lattice QCD data when T〉T_c,but show deviations at and below T_c. It can be concluded that the EoS of CJT is reliable when T〉T_c. Then,by adopting the hydrodynamic code UVH2＋1, we compare the CJT results of the multiplicity and elliptic flow v2 with the PHENIX data and the results from the original EoS in UVH2＋1. While the CJT results of multiplicities generally match the original UVH2＋1 results and fit the experimental data, the CJT results of v2 are slightly larger than the original UVH2＋1 results for centralities smaller than 40% and smaller than the original UVH2＋1 results for higher centralities.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11275097,11475085,11265017,and 11247219the Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No 1402006C+1 种基金the Natural Science Foundation of Jiangsu Province under Grant No BK20130078the Guizhou Province Outstanding Youth Science and Technology Talent Cultivation Object Special Funds under Grant No QKHRZ(2013)28
文摘We discuss the chiral phase transition of quantum chromodynamics （QCD） with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson-Schwinger equations, we focus particularly on the behavior of the widely accepted as well as interesting critical end point （CEP）, using a separable gluon propagator and a Gaussian gluon propagator. We find that there may be no CEP5 in the T-μ5 plane, and the phase transition in the T μ5 plane might be totally crossover. Our results have apparent consistency with the Lattice QCD calculation. On the other hand, our study may also provide some useful hints to some other studies related to μ5.
