检索结果-南通市图书馆

Derivation of a Closed Expression of the B-S Interaction Kernel for Quark-Antiquark Bound States

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2002年第10期38卷 433-446页

作者： su jun-Chen Center for Theoretical Physics Physics College Jilin University Changchun 130023 China

The interaction kernel in the Bethe-Salpeter (B-S) equation for quark-antiquark bound states is derivedfrom B-S equations satisfied by the quark-antiquark four-point Green's function. The latter equations are establishedbased on the equations of motion obeyed by the quark and antiquark propagators, the four-point Green's function andsome other kinds of Green's functions, which follow directly from the QCD generating functional. The derived B-Skernel is given by a closed and explicit expression which contains only a few types of Green's functions. This expressionis not only convenient for perturbative calculations, but also applicable for nonperturbative investigations. Since thekernel contains all the interactions taking place in the quark-antiquark bound states, it actually appears to be the mostsuitable starting point of studying the QCD nonperturbative effect and quark confinement.

关键词： B-S equation, interaction kernel, qq bound state

New Closed Expression of Interaction Kernel in Bethe-Salpeter Equation for Quark-Antiquark Bound States

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第3X期44卷 487-498页

作者： su jun-Chen Center for Theoretical Physics Physics College Jilin University Changchun 130023 China

The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived newly from QCD in the case where the quark and the antiquark are of different flavors. The technique of the derivation is the usage of the irreducible decomposition of the Green's functions involved in the Bethe-Salpeter equation satisfied by the quark-antiquark four-point Green's function. The interaction kernel derived is given a closed and explicit expression which shows a specific structure of the kernel since the kernel is represented in terms of the quark, antiquark and gluon propagators and some kinds of quark, antiquark and/or gluon three, four, five and six-point vertices. Therefore,the expression of the kernel is not only convenient for perturbative calculations, but also suitable for nonperturbative investigations.

关键词： Bethe-Salpeter equation interaction kernel quark-antiquark bound state

Probing neutron–proton effective mass splitting using nuclear stopping and isospin mix in heavy-ion collisions in GeV energy region

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第8期31卷 35-42页

作者： Fan Zhang jun su Department of Electronic Information and Physics Changzhi UniversityChangzhi 046011China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

The ramifications of the effective mass splitting on the nuclear stopping and isospin tracer during heavy-ion collisions within the gigaelectron volt energy region are studied using an isospin-dependent quantum molecular dynamics *** isotope probes,i.e.,a proton,deuteron,and triton,are used to calculate the nuclear *** to the mn*>mp*case,the mn*sults in a stronger stopping for protons but a weaker stopping for *** calculations of the isospin tracer show that the mn*>mp*parameter results in a higher isospin mix than the mn*suggested.

关键词： Neutron–proton effective mass splitting Nuclear stopping Isospin mix

Constraining symmetry energy at subnormal density by isovector giant dipole resonances of spherical nuclei

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2019年第6期43卷 80-84页

作者： jun su Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen University

In our previous study, the deduced Langevin equation has been applied to investigate the isoscalar giant monopole resonance. In the current study, the framework is extended to study the isovector giant dipole resonance(IVGDR). The potential well in the IVGDR is calculated by separating the neutron and proton densities based on the Hartree-Fock ground state. subsequently, the Langevin equation is solved self-consistently, resulting in the centroid energy of the IVGDR without width. The symmetry energy around the density of 0.02 fm^-3 contributes the most to the potential well in the IVGDR. By comparison with the updated experimental data of IVGDR energies in spherical nuclei, the calculations within 37 sets of Skyrme functionals suggest the symmetry energy to be in the range of 8.13-9.54 MeV at a density of 0.02 fm^-3.

关键词： isovector giant dipole resonance symmetry energy Skyrme energy-density functional

Microstructure and mechanical properties of 2219 aluminum alloy VPTIG welds during cyclic thermal treatment

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第10期41卷 3539-3545页

作者： Di-Yao su Hui-Jin Jin su-jun Wu School of Materials Scienceand Engineering Beihang UniversityBeijing 100191China

In this study,the effect of the cyclic thermal treatment(CTT) on the microstructure and mechanical properties of the 2219 Al alloy welds fabricated using variable polarity tungsten inert gas(VPTIG) arc welding method were investigated by optical microscope(OM),transmission electron microscope(TEM),and low-temperature tensile tests,with emphasis on precipitation evolution and property variation in different areas of the *** of the microhardness profile across the weld reveals that there are maximum and minimum hardness values in the heat-affected zone(HAZ) adjacent to the fusion boundary(FB).It is found that the maximum hardness value increases with the temperature cycles of the cyclic thermal treatment due to the formation of GuinierPreston(GP) zones,while the microhardness at other positions remains *** results show that the CCT results in an increase in the yield strength,but a decrease in the ductility of the weld joint.

关键词： 2219 aluminum alloy VPTIG weld Microstructure Microhardness

Inventory Games with Quantity Discount

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2021年第4期34卷 1538-1554页

作者： LI Wenzhong XU Genjiu su jun School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710072China School of Science Xi'an University of Science and TechnologyXi'an 710054China

Meca,et al.(2004)studied a class of inventory games which arise when a group of retailers who observe demand for a common good decide to cooperate and make joint *** this paper,the authors extend their model to the situation where the manufacturer provides the retailers with a price discount on purchases in excess of a certain order *** authors define the corresponding inventory game with quantity discount,and show that the inventory game has a nonempty ***,the authors propose a core allocation rule,the demand-proportionality rule,and characterize it by introducing efficiency,the retailer splitting property and continuity.

关键词： Allocation cooperative games inventory model quantity discount

πN Elastic Scattering and Resonances in Quark Potential Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第4期49卷 987-992页

作者： WANG Hai-jun su jun-Chen Center for Theoretical Physics Jilin University Changchun 130023 China

The quark potential model is used to investigate the low-energy elastic scattering of πN system. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the harmonic oscillator confining potential. By means of the resonating group method, a nonlocal effective potential for the πN system is derived from the interquark potentials and used to calculate the πN elastic scattering phase shifts. By considering the effect of QCD renormalization, the suppression of the spin-orbital coupling and the contribution of the color octet of the clusters （qq） and （qqq）, the numerical results are in fairly good agreement with the experimental data. The same model and method are employed to investigate the possible πN resonances. For this purpose, the resonating group equation is transformed into a standard Schrodinger equation in which the nonlocal effective πN interaction potential is included. Solving the Schrodinger equation by the variational method, we are able to reproduce the masses of some currently concerned πN resonances.

关键词： quark potential model pion-baryon interactions pion elastic scattering

Neutronic analysis of deuteron-driven spallation target

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第9期32卷 52-60页

作者： Wei-Wei Qiu Wu sun jun su Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

Deuteron-driven spallation targets have garnered attention recently because they can provide high-energy neutrons to transmute long-lifetime fission *** this study,the Geant4 toolkit was used to simulate the inter-action between a deuteron beam at 500 MeV and a com-posite target composed of alternating lead-bismuth eutectic(LBE)and *** water was used because it may be employed as a target *** energy spectrum,neu-tron yield,average energy,and total energy of the emitted neutrons were calculated for different thicknesses and thickness ratios between the LBE and *** a constant target thickness,the neutron yield increases with an increasing thickness ratio of LBE to H 2 O,while the aver-age energy of the emitted neutrons decreases with an increasing in the aforementioned thickness *** two aspects support the use of a pure target,either LBE or ***,with an increasing LBE-to-H 2 O thickness ratio,the total energy of the emitted neutrons increases and then *** result supports the addition of water into the LBE *** angular distributions of the emitted neutrons show that the rear of the target is suit-able for loading nuclear waste containing minor actinides and long-lifetime fission products.

关键词： Long-lived nuclear waste product Accelerator-driven sub-critical system Deuteron-induced spallation target Neutron spectrum

Secondary decay effects of the isospin fractionation in the projectile fragmentation at GeV/nucleon

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第12期31卷 122-128页

作者： Chen-Chen Guo jun su Long Zhu Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

The isospin fractionations in 124Sn,107Sn+120Sn at 600 MeV/nucleon,and 136Xe,124Xe+208Pb at 1000 MeV/nucleon are investigated by the isospin-dependent quantum molecular dynamics model coupled with the statistical code *** yield ratio as a function of the binding energy difference for light mirror nuclei 3H/3He,7Li/7Be,11B/11C,and 15N/15O is applied to estimate the ratio between neutrons and protons in the gas of the fragmenting *** comparing the estimated values resulting from the simulations with and without the GEMINI code,it was found that the secondary decay distorts the signal of the isospin *** minimize the secondary decay effects,the yield ratio of the light mirror nuclei 3H/3He as well as its double ratio between two systems with different isospin asymmetries of the projectiles is recommended as robust isospin observables.

关键词： Quantum molecular dynamics model(QMD) Isospin fractionation Secondary decay effect