A Generalized Bell Inequality and Decoherence for the K0KO

First, a generalized Bell inequality for different times and for different quasi-spin states is developed. We focus on special quasi-spin eigenstates and times. The inequality based on a local realistic theory is violated by the CP-violating parameter [1] if the quantum theory is used to recalculate the probabilities. Next, the quantum mechanical probabilities are modified by the decoherence approach, which enables the initial state to factorize spontaneously. In this way we get a lower limit for the decoherence parameter , which measures the degree of decoherence. This result is compared with the experimental value [2, 3] of the decoherence parameter deduced from the data of the CPLEAR experiment [4].     

SUSY—QCD Corrections to B^0—B^0 Mixing

We study the SUSY-QCD corrections to B^0-B^0 mixing with a reasonable SUSY parameter space and find that contribution from gluio is proportional to log(mg/μω) where μω is the weak interaction energy scale and by no means negligible.     

空间可展桁架拟静力展开分析的违约稳定方法

本文首次提出可展桁架拟静力展开分析的违约问题。根据受约束动力系统违约稳定与广义逆理论。采用位置违约的最小范数最小二乘解进行主动校正,有效降低位置违约,使展开过程位形模拟更准确。文中四个算例表明该方法正确、可靠。     

超子的稀有衰变及CP不守恒

简述了近些年来超子稀有衰变的理论和实验研究进展及其待解决的问题。简单地讨论了兰州CSR上进行超子稀有衰变实验的可能性。A brief review is given on recent studies of hyperon rare decay both in theory and experiment. Some problems which exist in the field are presented. A possibility of study on the rare decay of Hyperon ∑^＋ at CSR is discussed.     

Study Pure Annihilation Decays $B_s^0(\bar B_s^0)\rightarrow D^{\pm}\pi^{\mp}$ in PQCD Approach

The rare decays $B_s^0\rightarrow D^\pm \pi^\mp$ and $\bar B_s^0\rightarrow D^\mp \pi^\pm$ can occur only via annihilation-type diagrams in the standard model. In this paper, we calculate branching ratios of these decays in perturbative QCD approach ignoring soft final state interaction. From our calculation, we find that their branching ratios are at O(10^-6) with large CP asymmetry, which may be measured in LHC-b experiment in the future.     

Bilinear R-Parity Violation and τ干κ土 Mixing Production in e+e- Colliders

An extended minimum supersymmetric standard model, characterized by bilinear R-parity violations through the third generation lepton number (τ) in superpotential and the soft breaking SUSY tefms, is constructed. The masses of CP-odd Higgs bosons and those of charged Higgs bosons are estimated with proper formulation and possible parametrization. Several interestingfeatures, such as the mixing among τ lepton and charginos etc., are discussed precisely. Taking an example, we compute the ‘mixing production’ e⁺e^- → τ^干κ_i^土(i = 1, 2) cross sections in e⁺e^- colliders, where τ^干κ_i^土 (i = 1, 2) denote the physical τ lepton and the lightest charginos respectively.     

中性K介子系统唯象理论的修正

研究中性K介子系统的唯象理论,传统上采用的是建立在Wigner–Weisskopf近似基础上的有效哈密顿量理论.为了对此系统进行更精确地描述,采用了不作Wigner–Weisskopf近似的态演化矩阵,得到了描述此系统CP和CPT破坏的4个复参数(有效哈密顿量理论用2个复参数描述),并估计出实验精确到10^－14时,必须采用这种严格地描述,而不能再近似用有效哈密顿量理论.     

B and collider physics: Working group report

This report summarises the work done during WHEPP-6 (Institute of Mathematical Sciences, Chennai, India, Jan 3–15, 2000) in Working group on ‘B and collider physics’.     

Neutrino masses from SUSY: Different contributions and their implications

We discuss the various sources of neutrino masses in supersymmetric standard models with explicit lepton number violation. We show that the bilinear lepton number violating soft terms in models with either bilinear or trilinear lepton number violating couplings in the superpotential, play an important role in determining the neutrino mass spectrum. A comparative study of the neutrino mass spectrum and its implications for the present neutrino anomalies in these models is presented.