Heavy Charged Gauge Bosons with General CP Violating Couplings

Heavy gauge bosons such as W＇ are expected to exist in many extensions of the Standard Model. In this paper, the most general Lagrangian for the interaction of W＇ with top and bottom quarks is considered. This Lagrangian consists of V- A and V ＋ A structure with in general complex couplings. Such interactions produce an Electric Dipole Moment （EDM） for the top quark at one loop level. We predict the allowed ranges for the mass and couplings of W＇ by using the upper limit on the top quark EDM.     

Process e^-у→ e^-H in Littlest Higgs Model

In the context of the littlest Higgs （LH） model, we estimate the production cross section of the process e^-у→ e^-H in the future high-energy linear e^＋e^- collider （ILC） with the center-of-mass （CM） energy √S = 500 GeV. Our numerical results show that the contributions of the LH model Co this process are very small in most of the parameter space allowed by the electroweak precision measurement data, and are very diffcult to be detected in the future ILC experiments.     

B→K^＊у/Decay in Top-Quark Two-Higgs-Doublet Model

By employing the QCD factorization approach for the exclusive B→Vу decays, we study the exclusive decay B→K^＊у in the top-quark two-Higgs-doublet mode/（T2HDM）. Within the considered parameter space, we find the following conclusions （a） A hght charged-Higgs boson with a mass about 200 GeV is clearly excluded by the date of B→K^＊у decay, and this lower limit is comparable with that from the inclusive B→X8＊у decay; （b） The theoretical predictions for CP asymmetry of B→K^＊у in the T2HDM is always less than 1% in size; and （c） The isospin symmetry breaking for B→K^＊у decay in the SM and T2HDM considered here is around 6% in size and well consistent with the data and the general expectations.     

Functional Integrals and Collective Excitations in Boson-Fermion Model

In this paper, collective excitations in the boson-fermion model are investigated by means of functional integration method. The equations of energy gap and excitation spectrum are derived. Moreover, the Bose energy spectrum of zero wave vector Fermi fields is also calculated.     

A QCD Model Using Generalized Yang-Mills Theory

Generalized Yang-Mills theory has a covariant derivative, which contains both vector and scalar gauge bosons. Based on this theory, we construct a strong interaction model by using the group U（4）. By using this U（4） generalized Yang-Mills model, we also obtain a gauge potential solution, which can be used to explain the asymptotic behavior and color confinement.     

CERN可能探测到了希格斯粒子

 ２１世纪前夕,位于日内瓦附近的欧洲核子研究中心（简称ＣＥＲＮ）的物理学家们在大型正负电子对撞机（ＬＥＰ）上做出了令科学家们激动不已的工作：他们可能探测到了梦寐以求的希格斯粒子存在的迹象。 ＣＥＲＮ现在的这台正负电子对撞机的设计能量为１００吉电子伏（ＧｅＶ）。按人们原来推测,希格斯粒子的质量很可能在１５０吉电子伏左右,看来ＬＥＰ的能量是不够的。因此,ＣＥＲＮ几年前就开始筹建大型强子对撞机（ＬＨＣ）。这台对撞机将采用１４０００吉电子伏能量的质子一质子对撞,每年能产生８０万个顶夸克,发现希格斯粒子的机会因而会大得多。     

高能加速器近期的几个大工程

 量子论和相对论的发现和确立是20世纪基础科学的最伟大的事件,它们是现代科学技术的基础,改变了整个人类的生活方式。例如,人们制造了原子弹、氢弹,建造了核电站;随着集成电路的迅速发展,计算机已经普及到家庭,人们坐在家里就可通过网络了解全世界发生的事。20世纪后期,在总结新的实验事实的基础上,理论上创立了粒子物理的标准模型,所有核物理和粒子物理的实验结果都和标准模型的预言相一致。在人们为标准模型而欢呼的时候,实验上测量到存在中微子振荡现象,说明中微子有质量,这就超出了标准模型,说明标准模型需要完善和发展。     

基于微观IBM对电子-核散射及核电磁性质的研究(I) BE理论方案

从价核子自由度出发构造出核跃迁电荷/电流密度算符,采用Dyson玻色子展开技术给出了获取核玻色子形式跃迁电荷/电流密度有效算符的一种微观方法(BE方法).利用微观相互作用玻色子模型(IBM)提供的波函数可在玻色子态空间中求出核跃迁电荷/电流密度,结合电子-核散射以及核电磁跃迁的形式理论,建立了可研究电子-核散射各种形状因子,微分散射截面以及核约化跃迁几率、电磁多极矩、核态g因子等物理量的理论方案.在一种微观sdIBM-2框架下,结合现有理论方案,初步计算了     

封面照片说明

众所周知，科学家们首选的粒子物理标准模型为：所有物质是由6种夸克——上、下、奇异、粲、顶和底夸克——及比夸克轻得多的粒子，如电子和中微子等构成的。这些粒子的存在已被令人信服的证据所证实。但该模型还需要宇宙中存在有希格斯玻色子（Higgs Boson），希格斯粒子表现为引力，它在某些粒子周围很密集，而在另一些粒子附近则很少。正是这种聚集的密度赋予粒子以质量，因此，夸克很重，电子很轻，而光子则根本没有重量。     

轻子与中性弱规范玻色子的弹性散射

在Ｗｅｉｎｂｅｒｇ－Ｓａｌａｍ弱电统一理论中，计算了在新粒子产生阈能以下的轻子与中性弱规范子即Ｚ玻色子的弹性散射振幅，以及相应的散射截面角分布。