Double charged scalars of littlest higgs model in ee colliders
Ayse Cagil
备注:
Talk given in "Third International Workshop on Prospects for Charged Higgs Discovery at Colliders - CHARGED2010, September 27-30, 2010, Uppsala Sweden"
Little Higgs models contain heavy scalars in their content of particles as a result of extended symmetry group of SM. In the littlest Higgs model of little Higgs models there exists a new heavy scalar triplet.The physical states of this triplet contains a double charged scalar, a single charged scalar, as well as a neutral scalar and a neutral pseudo scalar. In little Higgs models a Majorana type mass term can also be implemented in Yukawa Lagrangian, resulting lepton flavor violation.
In this talk the pair productions of double charged scalars in the context of littlest Higgs model in $e^+e^-$ colliders are presented. Also the final signatures of double charged scalars will be analyzed depending on lepton flavor violation parameters. Finally it will be presented that if there is lepton flavor violation, double charged scalars can be observed without any SM background in $e^+e^-$ colliders with a collider signal of four leptons, otherwise if there is no lepton flavor violation they can be reconstructed with a background analysis.
Motivated by the search for flavor-changing neutral current (FCNC) top quark decays at the LHC, we calculate rare Higgs three body decay $H\rightarrow Wbc$ induced by top-Higgs FCNC coupling in the littlest Higgs model with T-parity(LHT). We find that the branching ratios of $H\rightarrow Wbc$ in the LHT model can reach $\mathcal O(10^{-7})$ in the allowed parameter space.
Associated production of single top and Higgs at the LHC in the littlest Higgs model with T-parity
在具有T宇称的最小Higgs模型(LHT)中,我们研究了在8和14 TeV LHC上与希格斯玻色子相关的$t$通道单顶产生.我们发现,与标准模型相比,该模型可以明显地增强横截面。通过在14 TeV LHC上利用$pp\rightarrow t(\rightarrow \ell^{+}νb)h(\rightarrow b\bar{b})j$进行简单的部分子级模拟,我们发现在有利的参数空间中信号的可观测性是有希望的。
Inspired by the recent CMS $h \to μτ$ excess, we calculate the lepton flavor violating Higgs decay $h \to μτ$ in the littlest Higgs model with T-parity (LHT). Under the constraints of $\ell_i \to \ell_j γ$, $Z \to \ell_i \bar{\ell}_j$ and Higgs data, we find that the branching ratio of $h \to μτ$ can maximally reach $\mathcal O(10^{-4})$. We also investigate the correlation between $h \to μτ$, $τ\to μγ$ and $Z \to μτ$, which can be used to test LHT model at future $e^+e^-$ colliders.
In the littlest Higgs model with T-parity, we study associated production of a Higgs and a single top quark at the 14 TeV LHC. We focus on the Higgs to two photons decay and the semileptonic top decay channel. By performing a fast detector simulation, we find that the $thj$ search in the selected channel can excluded the top partner mass $m_{T_{+}}$ up to 805 (857) GeV for case A (case B) at $2σ$ confidence level at 14 TeV LHC with the integrated luminosity $L= 3 \rm ab^{-1}$.
Determination of Littlest Higgs model parameters at the ILC
我们研究了在高能e+e-碰撞中最小Higgs模型的扩展规范扇区的影响。我们发现,在e+e- -> f fbar在500 GeV的质心能量的国际直线对撞机的搜索范围基本上涵盖了整个参数区域的最小希格斯模型是相关的规范层次问题。此外,我们表明,该通道提供了一个准确的确定的基本模型参数,精度为百分之几,只要大型强子对撞机测量的重中性规范场的质量。此外,我们还证明了在参数空间的一个重要区域,可以从过程e+e- -> Z higgs中观察到额外规范玻色子与轻Higgs的耦合。这使得确认的结构的取消希格斯质量平方发散,并将验证小希格斯机制。
In the framework of the littlest Higgs Model with T-parity, we discuss the top partner production at future $e^{+}e^{-}$ collider. We calculate the cross sections of the top partner production processes and associated production processes of Higgs and top partner under current constraints. Then, we investigate the observability of the T-odd top partner pair production through the process $e^{+}e^{-}\rightarrow T_{-}\bar{T}_{-}\rightarrow t\bar{t}A_{H}A_{H}$ in the $t\bar{t}$ di-lepton channel for two T-odd top partner mass $m_{T_{-}}$=603(708) GeV at $\sqrt{s}$=1.5 TeV. We analyze the signal s…
We first study the hadronic lepton flavor violating tau decays within the littlest Higgs model with T-parity (including one or two pseudoscalars, or a vector resonance). We consider the case where only T-odd particles and partner fermions contribute, and also its extension including Majorana neutrinos coming from an inverse seesaw. In both cases our mean values lie only one order of magnitude below current upper limits, strengthening the case of searching for these decays in the quest for new physics.
We show that the inverse see-saw is the most natural way of implementing neutrino masses in the Littlest Higgs model with T-parity. The three extra quasi-Dirac neutrinos are needed to cancel the quadratically divergent contributions of the mirror leptons to the Higgs mass. If the T-parity of the heavy neutrino singlets is chosen to be even, their contributions to lepton flavor violating transitions are one-loop finite. The most stringent limits on this scenario result from the non-observation of these transitions. Constraints on neutrino mixing imply an upper bound on the mass of the T-odd mir…