TC2模型下的顶夸克稀有衰变t→cV

在顶色辅助的人工色(TC2)理论框架下,研究了顶夸克稀有衰变t→cV过程.结果表明TC2模型预言的标量粒子top-pions和top-Higgs对顶夸克稀有衰变分支比的贡献可以使其比标准模型预言值大6—9个数量级.在大多数参数范围内,分支比的数量级为:Br(t→cg)～10^－5,Br(t→cZ)～10^－5,Br(t→cγ)～10^－7.在合理的参数范围内,顶夸克稀有衰变t→cV过程能够被未来的对撞机实验探测到.因此,顶夸克稀有衰变过程为我们提供了一种检验TC2理论的方法.     

在T2HDM模型中中性希格斯粒子对B→X_s1 1-衰变过程的影响(英文)

在T2HDM模型中计算了中性希格斯粒子圈图对稀有衰变过程B→X_s1 1-的贡献.通过计算发现:(a)中性希格斯粒子对衰变过程B→X_s1 1-的修正能够增强其标准模型的预言,但增幅很小;(b)在中性希格斯玻色子的质量大于100GeV和tanβ<40的情况下,中性希格斯粒子对稀有衰变过程B→X_s1 1-的分支比的贡献可忽略.     

C.D.Carone模型中的t夸克稀有衰变

最近C.D.Carone和H.Georgi提出了一种最小的Technicolor模型MTC,该模型具有一个无质量的标量子.本文计算了MTC模型对t夸克稀有衰变t→CV(V=Z、γ、g)的单圈修正.发现与标准模型相比,MTC的贡献要提高3—4个数量级.MTC模型对t→cV贡献为:B(t→cZ)～10^－7,B(t→cγ)～10^－9,B(t→cg)～10^－6.这为在未来加速器上探测t夸克的稀有衰变提供了很好的理论依据.     

在T2HDM模型中中性希格斯粒子对B→Xsl+l－衰变过程的影响

在T2HDM模型中计算了中性希格斯粒子圈图对稀有衰变过程B→X_sl⁺l^－的贡献. 通过计算发现: (a)中性希格斯粒子对衰变过程B→X_sl⁺l^－的修正能够增强其标准模型的预言, 但增幅很小; (b)在中性希格斯玻色子的质量大于100GeV和tanβ<40的情况下, 中性希格斯粒子对稀有衰变过程B→X_sl⁺l^－的分支比的贡献可忽略.     

味普适TC2模型与轻子味破坏衰变Z→lilj

讨论计算了味普适TC2模型预言的额外U(1)规范玻色子Z′对轻子味破坏(LFV)衰变Z→lilj过程的贡献.结果表明Z′对此过程有较大贡献,在合理的参数取值范围内,Z→τμ和Z→τe的分支比可以接近实验测量值的上限,而Z→μe过程的实验测量值上限给味普适TC2模型自由参数以严格的限制.     

一代Techniwlor模型对稀有衰变t→cV的贡献

计算了一代人工色(Technicolor)模型中的赝标哥尔斯通粒子对稀有衰变t→cV(V=Z、γ、g)的贡献.与标准模型的贡献相比,这种新的贡献提高了3—4个数量级.对适当的输入参数,一代Technicolor模型对t→cV分支比的贡献最大可达:B(t→cg)～10^－6,B(t→cZ)～10^－7,B(t→cγ)～10^－5.     

TOPCMTC模型中PGBs对top夸克稀有衰变的贡献

计算了top人工色援助的多标度人工色模型下top夸克稀有衰变t→cV(V=Z,γ,g)的单圈过程.发现在这个模型下,扩展的人工色相互作用对这些衰变提供主要的贡献,总的贡献能够把它们在标准模型下的分支比提高大约5–6个量级,对于一般的参数值,这些的结果分别是:B(t→cZ)～10^－6,B(t→cγ)～10^－7,B(t→cg)～10^－5.     

用Technicolor理论研究稀有辐射衰变Bc→Dsγ

在一代Technicolor(TCI)和带有一个无质量的标量二重态(TCⅡ)模型下,计算荷电的哥尔斯通粒子对衰变B_c→D_sγ的贡献,并把它们同标准模型的计算相比较,发现哥尔斯通粒子对电磁企鹅图的贡献很大(TCI下),在TCⅡ下贡献较小;而对弱湮没图的贡献可以忽略不计,还对同位旋三重态粒子π+p的质量进行了约束. 预言将来在LHC上能对不同模型下的分支比Br(B_c→D_sγ)的差异进行研究,进而对不同的模型进行检验.     

味普适TC2模型与轻子味破坏衰变Z→lilj

讨论计算了味普适TC2模型预言的额外U(1)规范玻色子Z′对轻子味破坏(LFV)衰变Z→l_il_j过程的贡献.结果表明Z′对此过程有较大贡献,在合理的参数取值范围内,Z→τμ和Z→τe的分支比可以接近实验测量值的上限,而Z→μe过程的实验测量值上限给味普适TC2模型自由参数以严格的限制.     

K介子稀有衰变及其对Multiscale WalkingTechnicolor模型的限制

在多标度人工色模型框架下计算了荷电PG玻色子π±1和π±8对K介子稀有衰变过程K⁺→π⁺νν,K_L→π⁰νν和K_L→μ⁺μ^－的企鹅图贡献.计算结果表明:(a)荷电PG玻色子可以对K介子稀有衰变分枝比给出1～3个量级的增强;(b)根据现有实验数据,K.Lane等人提出的多标度人工色模型基本被排除.     

粒子-转子模型和推转壳模型中的能谱统计分析

用粒子–转子模型和推转壳模型研究了6个粒子分别填充在单j壳和双j壳上的混沌行为.分析了单j壳和双j壳情况下能谱的最近邻能级间距分布和谱刚度随自旋及推转频率的变化,结果表明,当组态空间大小不变时,系统在双j壳(g_7/2+d_5/2)情况下比在单j壳(i_13/2)情况下更规则,而当组态空间从单j壳(i_13/2)扩大到双j壳(i_13/2+g_9/2)时,系统的混沌程度变化不大.同时比较了将6个粒子的两体相互作用分别取为δ力和对力时的系统的混沌行为     

Exact Recovery of Stochastic Block Model by Ising Model

In this paper, we study the phase transition property of an Ising model defined on a special random graph—the stochastic block model (SBM). Based on the Ising model, we propose a stochastic estimator to achieve the exact recovery for the SBM. The stochastic algorithm can be transformed into an optimization problem, which includes the special case of maximum likelihood and maximum modularity. Additionally, we give an unbiased convergent estimator for the model parameters of the SBM, which can be computed in constant time. Finally, we use metropolis sampling to realize the stochastic estimator and verify the phase transition phenomenon thfough experiments.     

Three-Dimensional Vertex Model Related BCC Model in Statistical Mechanics

In this paper, a three-dimensional vertex model is obtained. It is a duality of the three-dimensional integrable lattice model with N states proposed by Boos, Mangazeev, Sergeev and Stroganov. The Boltzmann weight of the model is dependent on four spin variables, which are the linear combinations of the spins on the corner sites of the cube, and obeys the modified vertex-type tetrahedron equation. This vertex model can be regarded as a deformation of the one related to the three-dimensional Baxter-Bazhanov model. The constrained conditions of the spectrums are discussed in detail and the symmetry properties of weight functions of the vertex model are presented.     

Solving the Generalized Higgs Model from the Generalized CRS Model

In this paper,we reveal a direct relation between the generalized one-dimensional Carinena-RanadaSantander(CRS) model and the radial part of two-dimensional generalized Higgs model.By this relation,we construct a series of quasi-exactly solutions for the two-dimensional Higgs model from a solved generalized CRS model.     

基于稀疏表示模型和自回归模型的高光谱分类

针对高光谱分类中对光谱信息和空间信息利用不足的问题,提出了一种基于稀疏表示模型和自回归模型相结合的分类算法。该算法利用稀疏表示模型和自回归模型,设计联合字典:在光谱维上,利用稀疏表示模型将高光谱的每个光谱向量表示为字典中训练样本的稀疏线性组合;在空间维上,利用自回归模型对每个光谱向量的8邻域进行约束。针对不同样本分别构造一个字典,在减少计算量的同时减小重构误差,最后在最小重构误差和邻域相关性的约束下求解稀疏表示问题,以最小重构误差为准则实现高光谱数据的分类。仿真结果表明,该方法能够有效地提高高光谱数据的分类精度。     

洛伦兹破缺的电动力学模型

由于宇宙常数的存在, 时空为渐近de Sitter(dS)的时空. 文中将静态dS度规作为时空的近似刻画, 研究了在此度规下的一个洛伦兹破缺的电动力学模型. 通过张量的标架场分解的方法, 得到了静态dS时空中的电磁场方程. 另外, 分别研究了静态dS时空中点电荷的静电场和圈电流的静磁场, 并且同时讨论了在此模型下的洛伦兹破缺效应.     

夸克-介子耦合模型

对夸克-介子耦合模型的研究进展及现状进行了简述.在此基础上,利用非拓扑孤子袋模型的思想和改进的夸克质量密度相关(IQMDD)模型,考虑夸克之间的排斥作用而加入ω介子,称为IQMDD-Ⅰ模型,得到了基态波函数和介子场满足的方程.利用平均场近似方法,通过得到的基态夸克波函数计算了核子的均方根半径和磁矩等可观测量,其结果与实验值吻合得较好.     

Noncommutative Sine-Gordon Model

The sine-Gordon model may be obtained by dimensional and algebraic reduction from (2+2)-dimensional self-dual U(2) Yang-Mills through a (2+1)-dimensional integrable U(2) sigma model. It is argued that the noncommutative (Moyal) deformation of this procedure should relax the algebraic reduction from U(2) U(1) to U(2)U(1) × U(1). The result are novel noncommutative sine-Gordon equations for a pair of scalar fields. The dressing method is outlined for constructing its multi-soliton solutions. Finally, the tree-level amplitudes demonstrate that this model possesses a factorizable and causal S-matrix in spite of its time-space noncommutativity.     

A New Car Following Model： Comprehensive Optimal Velocity Model

In this paper, we present a new car-following model, i.e. comprehensive optimal velocity model (COVM), whose optimal velocity function not only depends on the following distance of the preceding vehicle, but also depends on the velocity difference with preceding vehicle. Simulation results show that COVM is an improvement over the previous ones theoretically. Then, the stability condition of the model is obtained by the linear stability analysis, which has shown that the model could obtain a bigger stable region thanprevious models in the phase diagram. Through the nonlinear analysis, the Burgers, Korteweg-de Vries (KdV) and modified KdV (mKdV) equations are derived for the triangular shock wave, the soliton wave, and the kink-antikink soliton wave. At the same time, numerical simulations are also carried out to show that the model could simulate these density waves.