强子作为非拓扑孤粒子的SU（5）大统—模型（Ⅰ）

提出一种新的包含三代已知轻子与夸克的ＳＵ（５）大统—模型．按本模型，强子可看作由夸克形成的非拓扑孤粒子；轻子与夸克本质上是相同的，它们之间的差别是由对称性自发破缺造成的；在强子内部，夸克质量很小，其性质与已知夸克相同；在强子外部，夸克的性质与已知轻子相同，只是质量很重，并将很快衰变．本文除了定义严格守恒的电荷Ｑ０、费米子数Ｆ０外，还在孤粒子内部定义了近似守恒的内色荷、内电荷、内费米子数．已知ＳＵ（５）大统—模型的（Ｌ－Ｂ）守恒相应于本模型的Ｆ０守恒。     

An SU(5) Grand Unified Model with Hadrons as Nontopological Solitons(Ⅰ)

A new grand unified model containing the known three generations of quark and lepton in which hadrons are regarded as nontopological solitons formed from quarks is presented. According to the model leptons and quarks are the same in essence. The differences between them are caused by spontaneous symmetry breaking.When a quark is located inside a hadron, its properties will be the same as those of a known quark and its mass very small. When a quark is outside hadrons, its properties will be the same as those of a known lepton, its mass very large and it Will rapidly decay. Except defining charge Q0 and fermion number F0 which are exactly conserved, we also define interior colour, interior charge and interior fermion number approximatly conserved inside a hadron. The (L-B) conservation in the known SU(5) model corresponds to the fermion number number Fo conservation in the present model.     

Temperature-dependent theory of tunneling in the fractional quantum Hall effect

Recent experiments have studied the tunneling current between two edges of the same fractional quantum Hall liquid as a function of temperature and voltage. The experimental findings for low temperatures are at odds with the model where the edges are described as chiral Luttinger liquids, while the data at high temperatures are quite consistent with the same model. Here, we argue that a temperature dependence of the tunneling amplitude, not foreseen in previous works, can explain this discrepancy.     

Some neutral current effects in an SU(3)×U(1) gauge model

The anomalous magnetic moment of muon is calculated in anSU(3)×U(1) gauge model proposed by Gupta and Mani. We find the contribution due to the intermediate gauge bosons to be of the same order of magnitude as in Weinberg. Salam model. The deep-inelastic structure functions are also analysed in the same model and inequalities for the structure functions are obtained in the light-cone algebra approach.     

BRST analysis of the gauged SU(2) WZW model and Darboux’s transformations

The four dimensional SU(2) WZW model coupled to electromagnetism is treated as a constraint system in the context of the Batalin-Fradkin-Vilkovisky formalism. Common features with the Faddeev-Jackiw approach are stressed and the same results are obtained. The Darboux’s transformations which are used to diagonalize the canonical one-form in the Faddeev-Jackiw formalism, are shown to transform the fields of the model into BRST and σ closed. The same analysis is also carried out in the case of spinor electrodynamics.     

Some implications of the quark model for high energy scattering

The expressions for total scattering cross sections obtained from the quark model are expressed in a simple form which shows the dependence of the results on the assumptions. The results are shown to depend only on the value of six constants or “charges” defined for each hadron and to be otherwise independent of the structure. Any model which gives the same values of these charges gives the same result as the quark model. In particular, the results for processes which have odd signature t-channel quantum numbers hold in a quark model even with arbitrary mixtures of additional quarkantiquark pairs in the hadron wave function, provided that B, Y, and I are conserved.     

一种推广的混合自旋模型的临界温度曲线

本文提出了一种union jack晶格上推广的混合自旋模型。文中分别用平均场近似、自由费密近似及同普适类等标度变换理论对该模型进行了研究,分别得到了相互之间符合较好的临界温度曲线,并对不同处理方法进行了比较。在简化为特定可解模型时,得到与严格解一致的临界点。 关键词：     

Exactly soluble planar Ising models on compressible lattices

Two planar Ising models on compressible lattices are considered. The elastic forces act in the horizontal direction only and between nearest-neighbors, but are otherwise arbitrary. The nearest-neighbor exchange interaction is taken as constant for two spins with the same column index and depending on separation for spins on the same row. In the first model (A) the transition remains continuous, and Fisher's theory of renormalized exponents applies; in the second model (B) the additional constraint that spins on a column move as a unit changes the transition to first order.     

Higgsless Electroweak Model and contraction of gauge group

A modified formulation of the Electroweak Model with 3-dimensional spherical geometry in the target space is suggested. The free Lagrangian in the spherical field space along with the standard gauge field Lagrangian form the full Higgsless Lagrangian of the model, whose second order terms reproduce the same experimentally verified fields with the same masses as the Standard Electroweak Model. The vector bosons masses are automatically generated, so there is no need in special mechanism of spontaneous symmetry breaking. The limiting case of the modified Higgsless Electroweak Model, which corresponds to the contracted gauge group SU(2; j) × U(1) is discussed. Within framework of the limit model Z-boson, electromagnetic and electron fields are interpreted as an external ones with respect to W-bosons and neutrino fields. The W-bosons and neutrino fields do not effect on these external fields. The masses of the all particles remain the same, but the field interactions in contracted model are more simple as compared with the standard Electroweak Model.     

Asymmetric dark matter from hidden sector baryogenesis

We consider the production of asymmetric dark matter during hidden sector baryogenesis. We consider a particular supersymmetric model where the dark matter candidate has a number density approximately equal to the baryon number density, with a mass of the same scale as the b, c and τ. Both baryon asymmetry and dark matter are created at the same time in this model. We describe collider and direct detection signatures of this model.     

Schwinger model with higher derivative couplings

We study a version of the Schwinger model where fermion and gauge fields are coupled by means of higher derivatives. We show that, regardless of possible existence of ghosts and non-unitarity, the model is completely soluble and the anomalous axial divergence and the mass generated for the photon field are the same as in the usual model. The confinement of the electric charge is also discussed.     

A geometrical interpretation of the Pauli exclusion principle in classical field theory

It is shown that classical Dirac fields with the same couplings obey the Pauli exclusion principle in the following sense: If at a certain time two Dirac fields are in different states, they can never reach the same one. This is geometrically interpreted as analogous to the impossibility of crossing of trajectories in the phase space of a dynamical system. An application is made to a model in which extended particles are represented as solitary waves of a set of several fundamental, confined nonlinear Dirac fields, with the result that the same mechanism accounts both for fermion and boson behaviors.     

Asymmetric exclusion processes with site sharing in a one-channel transport system

This Letter investigates two-species totally asymmetric simple exclusion process (TASEP) with site sharing in a one-channel transport system. In the model, different species of particles may share the same sites, while particles of the same species may not (hard-core exclusion). The site-sharing mechanism is applied to the bulk as well as the boundaries. Such sharing mechanism within the framework of the TASEP has been largely ignored so far. The steady-state phase diagrams, currents and bulk densities are obtained using a mean-field approximation and computer simulations. The presence of three stationary phases (low-density, high-density, and maximal current) are identified. A comparison on the stationary current with the Bridge model [M.R. Evans, et al., Phys. Rev. Lett. 74 (1995) 208] has shown that our model can enhance the current. The theoretical calculations are well supported by Monte Carlo simulations.     

Critical behavior of a three-dimensional dimer model

The phase transition behavior of a dimer model on a three-dimensional lattice is studied. This model is of biological interest because of its relevance to the lipid bilayer main phase transition. The model has the same kind of inactive low-temperature behavior as the exactly solvable Kasteleyn dimer model on a two-dimensional honeycomb lattice. Because of low-temperature inactivity, determination of the lowest-lying excited states allows one to locate the critical temperature. In this paper the second-lowest-lying excited states are studied and exact asymptotic results are obtained in the limit of large lattices. These results together with a finite-size scaling ansatz suggest a logarithmic divergence of the specific heat aboveT _c for the three-dimensional model. Use of the same ansatz recovers the exact divergence (α=1/2) for the two-dimensional model.     

Mean Field Analysis of Large-Scale Interacting Populations of Stochastic Conductance-Based Spiking Neurons Using the Klimontovich Method

We investigate the dynamics of large-scale interacting neural populations, composed of conductance based, spiking model neurons with modifiable synaptic connection strengths, which are possibly also subjected to external noisy currents. The network dynamics is controlled by a set of neural population probability distributions (PPD) which are constructed along the same lines as in the Klimontovich approach to the kinetic theory of plasmas. An exact non-closed, nonlinear, system of integro-partial differential equations is derived for the PPDs. As is customary, a closing procedure leads to a mean field limit. The equations we have obtained are of the same type as those which have been recently derived using rigorous techniques of probability theory. The numerical solutions of these so called McKean–Vlasov–Fokker–Planck equations, which are only valid in the limit of infinite size networks, actually shows that the statistical measures as obtained from PPDs are in good agreement with those obtained through direct integration of the stochastic dynamical system for large but finite size networks. Although numerical solutions have been obtained for networks of Fitzhugh–Nagumo model neurons, which are often used to approximate Hodgkin–Huxley model neurons, the theory can be readily applied to networks of general conductance-based model neurons of arbitrary dimension.     

Boundary conditions for the subdiffusion equation

The boundary conditions for the subdiffusion equations are formulated using the continuous-time random walk model, as well as several versions of the random walk model on an irregular lattice. It is shown that the boundary conditions for the same equation in different models have different forms, and this difference considerably affects the solutions of this equation.     

Decoupling in theories with anomalies

We consider the appearance of infinities due to the triangle anomaly in the Weinberg model by introducing terms in the lagrangian which restore the Ward identities. It is then shown that these are not the same as the divergence which occur in the standard model if the quarks (which cancel the anomalies) are given a large mass. We have not succeeded in finding a model in which the infinities due to the anomalies are the leading effects of heavy fermions.     

Critical Behavior of the Gaussian Model with Periodic Interactions on Diamond—Type Hierarchical Lattices in External Magnetic Fields

The Gaussian spin model with periodic interactions on the diamond-type hierarchical lattices is constructed by generalizing that with uniform interactions on translationally invariant lattices according to a class of substitution sequences.The Gaussian distribution constants and imposed external magnetic fields are also periodic depending on the periodic characteristic of the interaction onds.The critical behaviors of this generalized Gaussian model in external magnetic fields are studied by the exact renormalization-group approach and spin rescaling method.The critical points and all the critical exponents are obtained.The critical behaviors are found to be determined by the Gaussian distribution constants and the fractal dimensions of the lattices.When all the Gaussian distribution constants are the same,the dependence of the critical exponents on the dimensions of the lattices is the same as that of the Gaussian model with uniform interactions on translationally invariant lattices.