arXiv subjects
Publications and source records attributed to Ren-Hong Fang.
With the consideration of identity principle and atomic shell structure, we calculated the ground state energy of Lithium atom and Beryllium atom based on variational method, which accords quite well with the experimental results.
We study the polarization of an electron scattered by different static potentials. The initial state of the electron is chosen as a wavepacket to construct the definite orbital angular momentum, and the final polarization of the electron, scattered by different static potentials such as vector, pseudovector, scalar and pseudoscalar potentials, is calculated. Numerical results show that, the sign of the polarization of the electron scattered by the vector potential is opposite to the other three cases, and the magnitude order of the polarization value is consistent with recent experimental result in the collision parameter range $0<b<2\,\mathrm{fm}$.
We investigate the axial vortical effect in a uniformly rotating sphere subject to finite size. We use MIT boundary condition to limit the boundary of the sphere. For massless fermions inside the sphere, we obtain the exact axial vector current far from the boundary that matches the expression obtained in cylindrical coordinates in the literature. On the spherical boundary, we find both the longitudinal and transverse(with respect to the rotation axis) components with magnitude depending on the colatitude angle. For massive fermions, we derive an expansion of the axial conductivity far from the boundary to all orders of mass whose leading order term agrees with the mass correction reported in the literature. We also obtain the leading order mass correction on the boundary which is linear, and stronger than the quadratic dependence far from the boundary. The qualitative implications on the phenomenology of heavy ion collisions are speculated.
We study the thermodynamics for a uniformly rotating system of chiral fermions under the uniform magnetic field. Then we obtain the mathematical expressions of some thermodynamic quantities in terms of the series with respect to the external magnetic field $B$, the angular velocity $Ω$ and the chemical potential $μ$, expanded around $B=0$, $Ω=0$ and $μ=0$. Our results given by such series are a generalization of the expressions available in the references simply corresponding to the lower-order terms of our findings. The zero-temperature limit of our results is also discussed.
We construct the grand partition function of the system of massive Dirac fermions in a uniform magnetic field from Landau levels, through which all thermodynamic quantities can be obtained. Making use of the Abel-Plana formula, these thermodynamic quantities can be expanded as power series with respect to the dimensionless variable $b=2eB/T^{2}$. The zero-field magnetic susceptibility is expanded at zero mass, and the leading order term is logarithmic. We also calculate scalar, vector current, axial vector current and energy-momentum tensor of the system through ensemble average approach. Mass correction to chiral separation effect is discussed. For massless chiral fermions, our results recover the chiral magnetic effect for right- and left-handed fermions, as well as chiral separation effect.
We construct the grand partition function of the system of chiral fermions in a uniform magnetic field from Landau levels, through which all thermodynamic quantities can be obtained. Taking use of Abel-Plana formula, these thermodynamic quantities can be expanded as series with respect to a dimensionless variable $b=2eB/T^{2}$. We find that the series expansions of energy density, pressure, magnetization intensity and magnetic susceptibility contain a singular term with $\ln b^{2}$, while particle number density, entropy density and heat capacity are power series of $b^{2}$. The asymptotic behaviors of these thermodynamic quantities in extreme conditions are also discussed.
Based on the result in our previous work, we calculate the polarization of quarks from parton scatterings in high energy heavy ion collisions. The result is compared with the STAR data at $\sqrt{s_{NN}}=200$ GeV.
Within Wigner function formalism, the chiral anomaly arises naturally from the Dirac sea contribution in un-normal-ordered Wigner function. For massless fermions, the Dirac sea contribution behaves like a 4-dimensional or 3-dimensional Berry monopole in Euclidian momentum space, while for massive fermions, although Dirac sea still leads to the chiral anomaly but there is no Berry monopole at infrared momentum region. We discuss these points explicitly in a simple and concrete example.
We concisely derive chiral magnetic effect through Wigner function approach for chiral fermion system. Then we derive chiral magnetic effect through solving the Landau levels of chiral fermions in detail. The procedures of second quantization and ensemble average lead to the equation of chiral magnetic effect for righthand and lefthand fermion systems. Chiral magnetic effect only comes from the contribution of the lowest Landau level. We carefully analyze the lowest Landau level, and find that all righthand (chirality is +1) fermions move along positive z-direction and all lefthand (chirality is -1) fermions move along negative z-direction. From this picture chiral magnetic effect can be explained clearly in a microscopic way.