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A Model-Independent Discussion of Quark Number Density and Quark Condensate at Zero Temperature and Finite Quark Chemical Potential

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Chinese physics Letters 2015年第12期32卷 14-17页

作者：徐书生蒋宇史潮崔钫宗红石 Department of physics Nanjing University Nanjing 210093 center for Statistical and Theoretical Condensed Matter physics Zhejiang Normal University Jinhua 321004 joint center for particle Nuclear Physics and Cosmology Nanjing 210093 State Key Laboratory of Theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190

Generally speaking, the quark propagator is dependent on the quark chemical potential in the dense quantum chromodynamics （QCD）. By means of the generating functional method, we prove that the quark propagator actually depends on p4 ＋ iμ from the first principle of QCD. The relation between quark number density and quark condensate is discussed by analyzing their singularities. It is concluded that the quark number density has some singularities at certain # when T = 0, and the variations of the quark number density as well as the quark condensate are located at the same point. In other words, at a certain # the quark number density turns to nonzero, while the quark condensate begins to decrease from its vacuum value.

关键词： QCD A Model-Independent Discussion of Quark Number Density and Quark Condensate at Zero Temperature and Finite Quark Chemical Potential

Ground State Properties of Superheavy Nuclei in Macroscopic-Microscopic Model

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Communications in Theoretical physics 2008年第9期50卷 707-714页

作者： ZHI Qi-Jun REN Zhong-Zhou ZHANG Xiao-Ping ZHENG Qiang School of Science Guizhou Normal University Guiyang 550001 China Department of physics Nanjing University Nanjing 210008 China center of Theoretical nuclear physics National Laboratory of Heavy-Ion Accelerator Lanzhou 730000 China joint center for particle Nuclear Physics and Cosmology Nanjing University Nanjing 210008 China

The ground state properties of superheavy nuclei are systematically calculated by the macroscopic-microscopic (MM) model with the Nilsson *** calculations well produced the ground state binding energies,α-decay energies,and half lives of superheavy *** calculated results are systematically compared with availableexperimental *** calculated results are also compared with theoretical results from other MM models and fromrelativistic mean-field *** calculations and comparisons show that the MM model is reliable in superheavy regionand that the MM model results are not very sensitive to the choice of microscopic single-particle potential.

关键词： macroscopic-microscopic model.superheavy nuclei binding energy half life

Theoretical Study on N=126 Shell Evolution

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Communications in Theoretical physics 2009年第8期52卷 323-328页

作者： SHENG Zong-Qiang REN Zhong-Zhou Department of physics Nanjing University Nanjing 210093 China center of Theoretical nuclear physics National Laboratory of Heavy-Ion Accelerator at Lanzhou Lanzhou 730000 China joint center for particle Nuclear Physics and Cosmology Nanjing 210093 China School of Science Anhui University of Science and Technology Huainan 232001 China

The nuclei around magic number N=126 are investigated in the deformed relativistic mean field (RMF)model with effective interactions *** focus investigations on the N=126 isotonic *** N=126 shellevolution is studied by analyzing the variations of two-neutron (proton) separation energies,quadruple deformations,single particle levels *** good agreement of two-neutron separation energies between experimental data and calculatedvalues is *** RMF theory predicts that the sizes of N=126 shell become smaller and smaller withthe increasing of proton number ***,the N=126 shell exists in our calculated region all *** tothe calculated two-proton separation energies,the RMF theory suggests ^(220)Pu is a two-proton drip-line nucleus in theN=126 isotonic chain.

关键词： shell evolution magic number N = 126 relativistic mean field theory

Modified entropic gravity revisited

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Science China(physics,Mechanics & Astronomy) 2014年第9期57卷 1623-1629页

作者： WANG Tower Department of physics East China Normal University Institute of nuclear and particle physics Astronomy and Cosmology Shanghai Jiao Tong University

Inspired by Verlinde’s idea,some modified versions of entropic gravity have been *** them in a unified formalism,herein we derive the generalized gravitational equations *** gravitational equations,the energy-momentum conservation law and cosmological equations are *** covariant conservation law of energy-momentum tensor severely constrains viable modifications of entropic gravity.A discrepancy arises when two independent methods are applied to the homogeneous isotropic universe,posing a serious challenge to modified models of entropic gravity.

关键词： classical general relativity modified gravity cosmology

Fermion-Boson Vertex at Finite Chemical Potential

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Communications in Theoretical physics 2007年第1期47卷 107-110页

作者： ZONG Hong-Shi FENG Hong-Tao HOU Feng-Yao SUN Wei-Min Department of physics Nanjing University Nanjing 2100937 China joint center for particle Nuclear Physics and Cosmology Nanjing 210093 China CCAST （World Laboratory） P.O. Box 8730 Beijing 100080 China

Based on the Ward-Takahashi identity at finite chemical potential and Lorentz structure analyms, we generalize the Ball-Chiu vertex to the case of nonzero chemical potential and obtain the general form of the frmionbo... 详细信息

关键词： Ward-Takahashi identity Ball-Chiu vertex finite chemical potential

Signal-background discrimination with convolutional neural networks in the PandaX-Ⅲ experiment using MC simulation

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Science China(physics,Mechanics & Astronomy) 2018年第10期61卷 51-59页

作者： Hao Qiao ChunYu Lu Xun Chen Ke Han XiangDong Ji SiGuang Wang School of physics and State Key Laboratory of nuclear physics and Technology and center for High Energy physics Peking University Beijing 100871 China Institute of particle and nuclear physics and School of physics and Astronomy Shanghai Jiao Tong University Shanghai Laboratory for Particle Physics and Cosmology Shanghai 200240 China Tsung-Dao Lee Institute Shanghai 200240 China

The PandaX-Ⅲ experiment will search for neutrinoless double beta decay of 136Xe with high pressure gaseous time projection chambers at the China Jin-Ping underground Laboratory. The tracking feature of gaseous detectors helps suppress the background level, resulting in the improvement of the detection sensitivity. We study a method based on the convolutional neural networks to discriminate double beta decay signals against the background from high energy gammas generated by 214Bi and 2^208 T1 decays based on detailed Monte Carlo simulation. Using the 2-dimensional projections of recorded tracks on two planes, the method successfully suppresses the background level by a factor larger than 100 with a high signal efficiency. An improvement of 62% on the efficiency ratio of Еs/√Еb is achieved in comparison with the baseline in the PandaX-Ⅲ conceptual design report.

关键词： neutrino double beta decay convolutional neural networks background suppression

Specific Heat of a Unitary Fermi Gas Including particle-Hole Fluctuation

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Chinese physics Letters 2016年第11期33卷 25-27页

作者：阮小霞宫昊石远美宗红石 Faculty of Science Jiangsu University Department of Mathematics and physics Bengbu College Department of physics and Electronic Engineering Nanjing Xiaozhuang University Department of physics Nanjing University State Key Laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of Sciences joint center for particle Nuclear Physics and Cosmology

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.

关键词： of in is Specific Heat of a Unitary Fermi Gas Including particle-Hole Fluctuation BEC BCS from heat

The Quark Number Susceptibility of QCD at Finite Temperature and Chemical Potential

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Chinese physics Letters 2013年第5期30卷 25-28页

作者： ZHU Hui-Xia SUN Wei-Min ZONG Hong-Shi Department of physics Nanjing UniversityNanjing 210093 The College of physics and Electronic Information Anhui Normal UniversityWuhu 241000 joint center for particle Nuclear Physics and CosmologyNanjing 210093 State Key Laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190

We calculate the quark number density and quark number susceptibility (QNS) of QCD at finite chemical potential μ and finite temperature T in the framework of a new nonperturbative QCD model. Analysis and discussions of the calculated results of the QNS are given. It is found that the quark number density has a singularity when μ comes close to a critical value μ0, and the QNS χ(μ,T) becomes discontinuous at some values of T. At high temperature the QNS approaches the free quark gas result, while at very low temperature the QNS equals zero. Importantly, the QNS shows a sudden increase near some temperature (T~120 MeV), which may be regarded as the signal of a crossover.

关键词： quark QCD singularity

Description of N=7～9 Isotones with a Modified Single-particle Potential

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Communications in Theoretical physics 2008年第12期50卷 1396-1400页

作者： GUO Yan-Qing REN Zhong-Zhou CHEN Yu-Qing Department of physics Nanjing University Nanjing 210008 China center of Theoretical nuclear physics National Laboratory of Heavy-Ion Accelerator Lanzhou 730000 China joint center for particle Nuclear Physics and Cosmology Nanjing 210008 China Department of physics and Electronic Engineering Hanshan Normal University Chaozhou 521041 China

We study the level structures of N = 7 - 9 isotones and their mirror nuclei in the framework of the single-particle potential model. Considering the limitation of the conventional potential-model calculation, the isospindependent 12 coupling is newly introduced in the average potential. The modified model gives a unified description for the structures of all studied nuclei. Galculations self-consistently produce the s-d level inversion in N = 9 isotones and their mirror nuclei. Meanwhile, the s-p level inversion in the mirror nuclei ^11Be and ^11N is reproduced. The study confirms the neutron halo structures in ^11Be（2s1/2）, ^11Be（1p1/2）, ^12B（2s1/2）, ^14B（2s1/2）, ^13C（2sl/2）, ^15C（2s1/2） and the proton halo structure in ^17F（2s1/2）. The agreement between theory and experiment indicates that the inclusion of the i2 coupling is a feasible way to explain the abnormal structures of exotic light nuclei.

关键词： modified single-particle potential level inversion l^2 coupling