Phase Structure in a Quark Mass Density-and-Temperature-Dependent Model

The phase diagram of bulk quark matter in equilibrium with a finite hadronic gas is studied. Different from previous investigations, we treat the quark phase with the quark mass density-and-temperature-dependent model to take the strong quark interaction into account, while the hadron phase is treated by hard core repulsion factor. It is found that the phase diagram in this model is, in several aspects, different from those in the conventional MIT bag model, especially at high temperature. The new phase diagram also has strong effects on the mass-radius relation of compact hybrid stars.     

超高能诱发核反应的国际合作实验研究进展

综述超高能诱发核反应的国际合作实验进展及相关的重离子物理研究现状.内容包括:1.有关夸克物质(夸克胶子等离子体QGP)的理论预言.2.超高能重离子碰撞的实验:(1)BNL/AGS能区的固定靶实验回顾;(2)CERN/SPS能区的固定靶实验回顾;(3)BNL/RHIC能区的对撞实验现状;(4)CERN/LHC能区的对撞实验现状.     

Fine splitting in the charmonium spectrum with a channel coupling effect

We study the fine splitting in the charmomium spectrum in the quark model with the channel coupling effect, including DD, DD^*, D^*D^* and D_sD_s, D_sD_s^*, D_s^*D_s^* channels. The interaction for channel coupling is constructed from the current-current Lagrangian related to the color confinement and the one-gluon exchange potentials. By adopting the massive gluon propagator from the lattice calculation in the nonperturbative region, the coupling interaction is further simplified to four-fermion interaction. The numerical calculation still prefers the assignment 1⁺⁺ of X(3872).     

Influence of quark energy loss on extracting nuclear sea quark distribution from nuclear Drell-Yan experimental data

By means of two typical kinds of quark energy loss parametrization and the nuclear parton distributions determined only with lepton-nuclear deep inelastic scattering experimental data, a leading order analysis is performed on the proton-induced Drell-Yan differential cross section ratios of tungsten versus deuterium as a function of the quark momentum fraction in the beam proton and target nuclei. It is found that the theoretical results with quark energy loss are in good agreement with the experimental data. The quark energy loss effect produces approximately 3% to 11% suppression on the Drell-Yan differential cross section ratios R_W/D in the range 0.05≤x₂≤0.3. The application of nuclear Drell-Yan data with heavy targets is remarkably subject to difficulty in the constraint of the nuclear sea quark distribution.     

An explanation of the△D35（1930） as a ρ△ bound state

Constituent quark models based on two-body potentials systematically overpredict the mass of △D35 （1930）. A possible solution to this problem comes out from the application of a schematic hybrid model, containing three-quark as well as meson-baryon components, to the light-quark baryon spectrum. The △D35（1930） and its partners △D33（1940） and△s31（1900） are found to contain a significant pA component. Then, through the use of the hidden gauge formalism, it is shown that these resonances can be dynamically generated from the ρ-△ interaction. In particular △D35（1930） can be interpreted as being essentially a ρ△ bound state. This interpretation suggests that the inclusion of ρ△ as an effective inelastic channel in data analyses could improve the extraction and identification of the resonance.     

Post-post-Newtonian deflection of light ray in multiple systems with PPN parameters

The post-Newtonian scheme in multiple systems with post-Newtonian parameters presented by Klioner and Soffel is extended to the post-post-Newtonian (PPN) order for light propagation problem in the solar system.Under considering the solar system experiment requirement,a new parameter ε is introduced.This extension does not change the virtue of the scheme on the linear partial differential equations of the potential and vector potential mentioned in previous work.Furthermore,this extension is based on the former work done by Richter and Matzner in one global system theory.As an application,we also consider the deflection of light ray in the global coordinates.And the deflection angle of light ray is obtained with post-Newtonian parameters.