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تسجيل مستخدم جديدThe flavor-changing top-charm quark production in the littlest Higgs model with T parity at the ILC
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With high luminosity and energy at the ILC and clean SM backgrounds, the top-charm production at the ILC should have powerful potential to probe new physics. The littlest Higgs model with discrete symmetry named T-parity(LHT) is one of the most promising new physics models. In this paper, we study the FC processes $e^+e^-(gammagamma)to tbar{c}$ at the ILC in the LHT model. Our study shows that the LHT model can make a significant contribution to these processes. When the masses of mirror quarks become large, these two processes are accessible at the ILC. So the top-charm production at the ILC provides a unique way to study the properties of the FC couplings in the LHT model and furthermore test the model.
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The littlest Higgs model with discrete symmetry named T-parity(LHT) is an interesting new physics model which does not suffer strong constraints from electroweak precision data. One of the important features of the LHT model is the existence of new s
ource of FC interactions between the SM fermions and the mirror fermions. These FC interactions can make significant loop-level contributions to the couplings $tcV$, and furthermore enhance the cross sections of the FC single-top quark production processes. In this paper, we study some FC single-top quark production processes, $ppto tbar{c}$ and $ppto tV$, at the LHC in the LHT model. We find that the cross sections of these processes are strongly depended on the mirror quark masses. The processes $ppto tbar{c}$ and $ppto tg$ have large cross sections with heavy mirror quarks. The observation of these FC processes at the LHC is certainly the clue of new physics, and further precise measurements of the cross scetions can provide useful information about the free parameters in the LHT model, specially about the mirror quark masses.
In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some botto
m and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., $e^+e^-to bbar{s}$ and $gammagammato bbar{s}$. The results show that the production rates of these processes are sizeable for the favorable values of the parameters. Therefore, it is quite possible to test the LHT model or make some constrains on the relevant parameters of the LHT through the detection of these processes at the ILC.
We re-examine lepton flavor violation (LFV) in the Littlest Higgs model with T--parity (LHT) including the full T--odd (non-singlet) lepton and Goldstone sectors. The heavy leptons induce two independent sources of LFV associated with the couplings n
ecessary to give masses to the T--odd mirror fermions and to their partners in right-handed $SO(5)$ multiplets, respectively. The latter, which have been neglected in the past, can be decoupled from gauge mediated processes but not from Higgs mediated ones and must therefore also be included in a general analysis of LFV in the LHT. We also further extend previous analyses by considering on-shell $Z$ and Higgs LFV decays together with the LFV processes at low momentum transfer. We show that current experimental limits can probe the LHT parameter space up to global symmetry breaking scales $f sim 10$ TeV. For lower $f$ values $gtrsim 1$ TeV, $mu-e$ transitions require the misalignment between the heavy and the Standard Model charged leptons to be $lesssim 1 , %$. Future LFV experiments using intense muon beams should be sensitive to misalignments below the per mille level. For $tau$ LFV transitions, which could potentially be observed at Belle II and the LHC as well as future lepton colliders, we find that generically they can not discriminate between the LHT and supersymmetric models though in some regions of parameter space this may be possible.
Lepton flavor violation in tau and mu processes is studied in the littlest Higgs model with T-parity. We consider various asymmetries defined in polarized tau and mu decays. Correlations among branching ratios and asymmetries are shown in the followi
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