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The π and Tensor Vacuum Susceptibilities from the Global Color Symmetry Model

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Communications in Theoretical Physics 2002年第7期38卷 75-80页

作者： zong Hong-shi PING Jia-Lun YANG Hong-Ting LU Xiao-Fu WANG Fan Department of Physics Nanjing University Nanjing 210093 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Department of Physics Nanjing Normal University Nanjing 210097 China Department of Physics Nanjing University Nanjing 210093 China Department of Physics Sichuan University Chengdu 610064 China Department of Physics Nanjing University Nanjing 210093 China

A modified method for calculating the nonperturbative quark vacuum condensates from the global color symmetry model is derived. Within this approach it is shown that the treatment of quark vacuum condensates is different from that in the previous studies. As a special case we calculate the π and tensor vacuum susceptibilities. A comparison with the results of the other nonperturbative QCD approaches is given.

关键词： nonperturbative methods in QCD, global color symmetry model

QCD Sum Rule External Field Approach and Vacuum Susceptibilities

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Communications in Theoretical Physics 2002年第10期38卷 475-482页

作者： zong Hong-shi PING Jia-Lun CHANG Chao-His WANG Fan ZHAO En-Guang Department of Physics Nanjing University Nanjing 210093 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Department of Physics Nanjing Normal University Nanjing 210097 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Institute of Theoretical Physics Academia Sinica P.O. Box 2735 Beijing 100080 China Department of Physics Nanjing University Nanjing 210093 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Institute of Theoretical Physics Academia Sinica P.O. Box 2735 Beijing 100080 China

Based on QCD sum rule three-point and two-point external field formulas respectively, the vector vacuumsusceptibilities are calculated at the mean-field level in the framework of the global color symmetry model. It is shownthat the above two approaches of determination of the vector vacuum susceptibility may lead to different results. Thereason of this contradiction is discussed.

关键词： nonperturbative methods in QCD, global color symmetry model

A New Approach for Calculating Spin Susceptibility in QED_3

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Communications in Theoretical Physics 2008年第3期49卷 703-706页

作者： HU Fei JIANG Yu FENG Hong-Tao SUN Wei-Min zong Hong-shi Department of Physics Nanjing University Nanjing 210093 China joint Center for Particle Nuclear Physics and Cosmology Nanjing 210093 China

Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influence of the full vertex function is included. The numerical values of the staggered spin susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson-Schwinger approach. A comparison between the result calculated using the full vertex and that using the bare vertex is given.

关键词： QED3 spin susceptibility Dyson-Schwinger approach

Critical Number of Fermion Flavors at Finite Chemical Potential in QED3

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Communications in Theoretical Physics 2005年第6X期44卷 1055-1060页

作者： FENG Hong-Tao HE Xiang HOU Feng-Yao SUN Wei-Min zong Hong-shi Department of Physics Nanjing University Nanjing 210093 China Joint Center for Particle Nuclear Physics and Cosmology Nanjing 210093 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China

We propose a new method for calculating the dressed fermion propagator at finite chemical potential in QED3 under the rainbow approximation of Dyson-Schwinger equation. In the above approximation, we show that the dressed fermion propagator at finite chemical potential # has the form S（p） = iγ.p^-A（p^-2）＋ B（ p^-2） with p^-μ= （p^-1p3 ＋ iμ）. Using this form of fermion propagator at nonzero chemical potential, we investigate the Dyson-Schwinger equation for the dressed fermion propagator at finite chemical potential and study the effects of the chemical potential on the critical number of the fermion flavors.

关键词： DS equation chemical potential critical number of the fermion flavors

Behavior of Vacuum Polarization of Gauge-Boson and Wavefunction Renormalization Factor of Fermion in Different Phases of QED3

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Communications in Theoretical Physics 2006年第2期45卷 315-319页

作者： YANG Qiao-Li HE Xiang FENG Hong-Tao SUN Wei-Min zong Hong-shi Depaxtment of Physics Nanjing University Nanjing 210093 China Laboratory of Solid State Microstructures Nanjing University Nanjing 210008 China Joint Center for Particle Nuclear Physics and Cosmology Nanjing University Nanjing 210093 China CCAST （World Laboratory） P.O. Box 8730 Beijing 100080 China

We investigate the behavior of the vacuum polarization of the gauge-boson Ⅱ and the wave-function renormalization factor of the fermion A in QEDs, using the coupled Dyson-Schwinger equations for the gauge-boson and fermion propagator. Using several different ansatze for the fermion-gauge-boson vertex, we find that the wave-function renormalization factor .4 and especially the vacuum polarization Ⅱ have different behaviors in the dynamical chiral symmetry breaking phase and in the chiral symmetric phase and hence in the phenomenological applications of QED3 one should choose different forms of gauge-boson propagator for these two phases. We also find that when adopting a specific ansatze of the fermion-gauge-boson vertex （ansatze （3）） the vacuum polarization function equals its one-loop perturbative result in the chiral symmetric phase. This fact suggests that in QEDs the Wigner vacuum corresponds to the perturbative vacuum.

关键词： DS equations vacuum polarization of gauge-boson DCSB phase symmetric phase

Cosmic acceleration caused by the extra-dimensional evolution in a generalized Randall-Sundrum model

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Chinese Physics C 2020年第11期44卷 213-219页

作者： Guang-Zhen Kang De-Sheng Zhang Chao shi Long Du Dan Shan Hong-shi zong School of Science Yangzhou Polytechnic InstituteYangzhou 225127China Department of Physics Nanjing UniversityNanjing 210093China School of Science Changzhou Institute of TechnologyChangzhou 213032China Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China School of Science Guangxi University of Science and TechnologyLiuzhou 545006China Department of Physics Anhui Normal UniversityWuhu 241000China Nanjing Proton Research and Design Center Nanjing 210093China

We investigate an(n+1)-dimensional generalized Randall-Sundrum model with an anisotropic metric which has three different scale *** obtains a positive effective cosmological constant Ωeff∼10^−124(in Planck units),which only needs a solution kr≃50−80 without fine *** the visible and hidden brane tensions are positive,which renders the two branes ***,we find that the Hubble parameter is close to a constant in a large region near its minimum,thus causing the acceleration of the ***,the scale of extra dimensions is smaller than the observed scale but greater than the Planck *** may suggest that the observed present acceleration of the universe is caused by the extra-dimensional evolution.

关键词： Hubble parameter extra dimensions anisotropic

Simulations of a two-stream backward-wave oscillator with a slot-hole structure

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Chinese Physics B 2012年第1期21卷 518-523页

作者： shi zong-Jun Tang Xiao-Pin Yang Zi-Qiang Lan Feng Liang Zheng Terahertz Research Centre School of Physical ElectronicsUniversity of Electronic Science and Technology of ChinaChengdu 610054China

We study a two-stream backward-wave oscillator with a slot-hole structure at short millimeter waves with the help of a three-dimensional particle-in-cell simulation. In order to increase the interaction region of the electron beam, the efficiency and the output power, a slot-hole loaded rectangular waveguide structure used as the high-frequency system is proposed. Based on the mechanism of the backward-wave oscillator, a slow-wave oscillator with a frequency of 0.14 THz is designed. The simulations show that the output power and the efficiency of the oscillator can be enhanced due to the coupling between the two beams through the slot holes. The interaction efficiency is 5.18%, and the starting current density is below 5 A. cm^-2 for the two beams. These attractive results indicate that, based on the two-stream backward-wave oscillator, we can get short millimeter wave sources with high power and low current density.

关键词： slot-hole structure short millimeter wave two-stream backward-wave oscillator

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丝虫病传播阈值的研究

中国寄生虫学与寄生虫病杂志 1994年第1期12卷 1-6页

作者： shi zong Jun 中国预防医学科学院寄生虫病所上海

在浙江、河南等１１个省、自治区选择经过海群生防治、丝虫和蚊媒种类有代表性的地方建点２１个，不采取防治措施，纵向观察３－５年。主要结果：①２７９例残存微丝蚴血症者大部陆续自然转阴；②微丝蚴率，２０个点逐年下降，１个点徘... 详细信息

在浙江、河南等１１个省、自治区选择经过海群生防治、丝虫和蚊媒种类有代表性的地方建点２１个，不采取防治措施，纵向观察３－５年。主要结果：①２７９例残存微丝蚴血症者大部陆续自然转阴；②微丝蚴率，２０个点逐年下降，１个点徘徊在原水平；③１２个点的蚊媒已未查见幼丝虫。结果表明，在以人饵蚊帐诱捕法调查，蚊媒叮人率为２０－５０只／人、夜，和有４０％左右居民合理使用蚊帐防蚊的情况下，２０个点的微丝蚴率，班氏丝虫病点≤１．７１％，马来丝虫病点≤１．５５％，残存微丝蚴血症者６０μｌ血平均密度大多在３－１０条，只有个别的密度较高，丝虫病的传播处于阈值以下，趋于阻断；１个徘徊于原水平的马来丝虫病点，微丝蚴率为２．３１％，有１例微丝蚴血症者密度较高（５４条／６０μｌ），处于丝虫病传播临界水平。

关键词：传播阈值丝虫病马来丝虫病

Skyrmion stability at finite isospin chemical potential and temperature

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Chinese Physics C 2020年第1期44卷 105-110页

作者： Wen-Li Yuan Zhen-Ni Xu Jin-Li Zhang Hong-shi zong Department of Physics Nanjing UniversityNanjing 210093China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal UniversityNanjing 210023China Joint Center for Particle Nuclear Physics and CosmologyNanjing 210093China State Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsCASBeijing 100190China

The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is *** also explore some properties of the skyrmion as function of i.e.,the isoscalar rms radius and the isoscalar magnetic rms ***,considering the finite temperature effect on the skyrmion mass,we obtain a critical temperature T_c,using the profile function of the skyrmion,above which the skyrmion mass does not have a minimum,which can be interpreted as the occurrence of the deconfinement phase transition.

关键词： skyrme model isospin chemical potential skyrmion stability