分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要: We propose to probe the top-color-assisted technicolor (TC2) model from the top-charm associated production at the CERN LHC, which is highly suppressed in the standard model. Because of the flavor-changing couplings of the top quark with the scalars (top-pions and top-Higgs-bosons) in the TC2 model, the top-charm associated production can occur via both the s-channel and t-channel parton processes by exchanging a scalar field at the LHC. We examine these processes through Monte Carlo simulation and find that they can reach the observable level at the LHC in quite a large part of the parameter space of the TC2 model.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要: We examined the rare decays B --> X(x)e(+)e(-) and B-x --> e(+)e(-)gamma in the minimal supersymmetric model with large tan beta. Taking into account the effects of the gluino-loop and neutralino-loop with neutral Higgs exchange, we found that for a large tan beta the neutral Higgs exchanging diagrams could enhance Br(B --> X(s)tau(+)tau(-)) by a factor of 5 and Br(B-s --> tau(+)tau(-)gamma) by a couple of orders in some part of supersymmetric parameter space allowed by current experiments such as b --> sgamma, B --> K((*))e(+)e(-) and B-s --> e(+)e(-). The forward-backward asymmetry and the distributions of differential branching ratios are also found to differ significantly from the standard model results. Such enhanced branching ratios reach the level of 10(-5) and thus might be observable in the new generation of B experiments. (C) 2002 Elsevier Science B.V. All rights reserved.