A New Approach for Calculating Vacuum Susceptibility

Based on the Dyson-Schwinger approach, we propose a new method for calculating vacuum susceptibilities. As an example, the vector vacuum susceptibility is calculated. A comparison with the results of the previous approaches is presented.     

Explicit and Dynamical Chiral Symmetry Breaking in an Effective Quark-Quark Interaction Model

A method for obtaining the small current quark mass effect on the dressed quark propagator from an effective quark-quark interaction model is developed. Within this approach both the explicit and dynamical chiral symmetry breakings are analysed. A comparison with the previous results is given.     

Quark Virtuality and QCD Vacuum Condensates

Based on the Dyson-Schwinger equations (DSEs) in the ‘rainbow‘ approximation, we investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, we calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are λu,d^2 0.7 GeV^2 for u, d quarks, and λs^2=1.6 GeV^2 for s quark. Our theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions.     

更精确地研究核子

位于美国弗吉尼亚洲的ThomasJefferson国家加速器实验室的一群国际科学家们 ,共同对质子内夸克自旋是如何取向的问题进行研究 .粗略地说 ,夸克自旋可以看成是一个微小的磁棒 ,指向某一确定的方向并具有一定的强度 .有关夸克自旋的信息可提供这些基本粒子在核子 (如中子与质子 )     

Spin Correlations in Top Quark Pair Production Near Threshold at the e^＋e^- Linear Collider

We investigate the spin correlations in top quark pair production near the threshold at the e^ e^- linear collider. Comparing with the results above the threshold region, we find that near the threshold region the off-diagonal basis, the optimized decomposition of the top quark spins above the threshold region, does not exist, and the beamline basis is the optimal basis, in which there are the dominant spin components: the up-down (UD) component for e^-le^ scattering and the down-up (DU) component for eR^-e^ scattering can make up more than 50% of the total cross section,respectively.     

Bulk viscosity of hot dense Quark matter in the PNJL model

Starting from the Kubo formula and the QCD low energy theorem, we study the the bulk viscosity of hot dense quark matter in the PNJL model from the equation of state. We show that the bulk viscosity has a sharp peak near the chiral phase transition, and that the ratio of bulk viscosity over entropy rises dramatically in the vicinity of the phase transition. These results agree with those from the lattice and other model calculations. In addition, we show that the increase of chemical potential raises the bulk viscosity.     

谈谈高能物理

 一、高能物理学科的产生和它的根本目的 高能物理又称粒子物理(又称粒子物理,因为在高能物理研究的能量区域,一切物质现象都可归结为构成物质的基本组份在基本作用力作用下产生的现象),它是研究物质的基本组份及其相互作用的基础学科,是当代物理学前沿。