Left-right Twin Higgs Model Research Articles

Probing lepton flavor violation signal via γγ→l¯ilj in the left-right twin Higgs model at the ILC

To explain the small neutrino masses, heavy Majorana neutrinos are introduced in the left-right twin Higgs model. The heavy neutrinos, together with the charged scalars and the heavy gauge bosons, may contribute large mixings between the neutrinos and the charged leptons, which may induce some distinct lepton flavor violating processes. We will check the \bar \ell_i \ell_j (i,j= e,\mu,\tau,i\neq j) productions in the \gamma\gamma collision in the left-right twin Higgs model, and find that the production rates may be large in some specific parameter space, in the optimal cases even possible to be detected with reasonable kinematical cuts. we have also shown that these collisions can constrain effectively the model parameters such as the Higgs vacuum expectation value and the right-handed neutrino mass, etc., and may serve as a sensitive probe of this new physics model.

Twin Higgs model with T parity

In twin Higgs models, a discrete ${\mathbb{Z}}_{2}$ symmetry between the standard model Higgs and the twin Higgs is introduced to address the hierarchy problem. In this work, we propose another discrete symmetry in twin Higgs: the $T$ parity, which maps the twin Higgs quadruplet into its mirror copy. The $T$ parity brings us a whole group of $T$-odd particles, and leads to a promising dark matter candidate. We present one realization of the $T$-parity twin Higgs scenario by implementing the $SU(2{)}_{L}\ifmmode\times\else\texttimes\fi{}SU(2{)}_{R}\ifmmode\times\else\texttimes\fi{}U(1{)}_{1}\ifmmode\times\else\texttimes\fi{}U(1{)}_{2}$ gauge symmetry in the left-right twin Higgs model. In this specific setup, the $T$-odd $U(1)$ gauge boson could be the dark matter candidate, and the $T$-odd particles have very distinct and interesting phenomenology.

Higgs and Single Top Associated Production at the LHC in the Left-Right Twin Higgs Model**Supported by the National Natural Science Foundation of China under Grant No. U1404113, the Aid Project for the Mainstay Young Teachers in Henan Provincial Institutions of Higher Education of China under Grant Nos. 2016GGJS-135, 2014GGJS-283, and Colleges and Universities in Henan Province Key Scientific Research Project

In the framework of the left-right twin Higgs (LRTH) model, we study the Higgs boson and single top quark associated production at the LHC. We investigate the processes , and at the 8(14) TeV LHC and find that the production cross sections of the three processes can be enhanced at different levels. Among them, the production cross section of the process is enhanced significantly due to the contribution of the new particles predicted by the LRTH model.

Single Higgs boson production at the ILC in the left-right twin Higgs model

In this work, we analyze three dominant single SM-like Higgs boson production processes in the left-right twin Higgs model (LRTHM): the Higgs-strahlung (HS) process , the vector boson fusion (VBF) process and the associate production with top pair process for three possible energy stages of the International Linear Collider (ILC), and compared our results with the expected experimental accuracies for various accessible Higgs decay channels. The following observations have been obtained. (1) In the reasonable parameter space, the LRTHM can generate moderate contributions to theses processes with polarized beams. (2) Among various Higgs boson decay channels, the signal strength is the most sensitive to the LRTHM due to the high expected precision. For the production process, the absolute value of may deviate from the SM prediction by over 8.7% and thus may be detectable at the proposed ILC with TeV. (3) ILC experiments may give a strong limit on the scale parameter f: for the case of ILC-250 GeV, for example, the lower limit for parameter f of the LRTHM is f > 1150 GeV at the level.

Higgs boson production and decay at [formula omitted] colliders as a probe of the Left–Right twin Higgs model

In the framework of the Left–Right twin Higgs (LRTH) model, we consider the constrains from the latest search for high-mass dilepton resonances at the LHC and find that the heavy neutral boson ZH is excluded with mass below 2.76 TeV. Under these constrains, we study the Higgs–Gauge coupling production processes e+e−→ZH, e+e−→νeνe¯H and e+e−→e+e−H, top quark Yukawa coupling production process e+e−→tt¯H, Higgs self-couplings production processes e+e−→ZHH and e+e−→νeνe¯HH at e+e− colliders. Besides, we study the major decay modes of the Higgs boson, namely h→ff¯(f=b,c,τ), VV⁎(V=W,Z), gg, γγ. We find that the LRTH effects are sizable so that the Higgs boson processes at e+e− collider can be a sensitive probe for the LRTH model.

Constraining dark matter in the LRTH model with latest LHC, XENON100 and LUX data

In the left–right twin Higgs (LRTH) model, the neutral is a candidate for weakly interacting massive particle dark matter (DM). If its mass is lighter than half of the standard model-like Higgs boson h, the new invisible decay will become open. In this paper, we examine the status of a light DM () under current experimental constraints including the latest LHC Higgs data, the XENON100 and LUX limit on the DM scattering off the nucleon. The following observations have been obtained: (i) the current ATLAS (CMS) measurements of can exclude the invisible Higgs branching ratio larger than 34% (48%) at level; (ii) the Global fits to the latest LHC and Tevatron Higgs data provide a stronger constraint: (30%) at () level, which could be tested in the LHC experiments; (iii) for the spin-independent scattering cross section off the nucleon, the recent XENON100 (LUX) data can exclude the invisible decay rate larger than 50% (25%); and (iv) the results of direct DM searches with LUX can give strong constraint on the viable parameter space of in this LRTH model.

The production and decay of the top partner T in the left–right twin Higgs model at the ILC and CLIC

The left–right twin Higgs model (LRTHM) predicts the existence of the top partner T. In this work, we make a systematic investigation for the single and pair production of this top partner T through the processes: e+e−→tT¯+Tt¯ and TT¯, the neutral scalar (the SM-like Higgs boson h or neutral pseudoscalar boson ϕ0) associate productions e+e−→tT¯h+Tt¯h, TT¯h, tT¯ϕ0+Tt¯ϕ0 and TT¯ϕ0. From the numerical evaluations for the production cross sections and relevant phenomenological analysis we find that (a) the production rates of these processes, in the reasonable parameter space, can reach the level of several or tens of femtobarns; (b) for some cases, the peak value of the resonance production cross section can be enhanced significantly and reaches to the level of pb; (c) the subsequent decay of T→ϕ+b→tb¯b may generate typical phenomenological features rather different from the signals from other new physics models beyond the standard model (SM); and (d) since the relevant SM background is generally not large, some signals of the top partner T predicted by the LRTHM may be detectable in the future ILC and CLIC experiments.

Production and decays of a light ϕ 0 in the LRTH model under the LHC Higgs data

In this paper we study the production and decays of a light pseudoscalar boson $\phi^0$ with $m_{\phi^0} \leq m_h/2$ appeared in the left-right twin Higgs (LRTH) model, and explore its phenomenological consequences when the latest LHC Higgs data are taken into account. We found that (a) the decay rate $Br(h\to \phi^0\phi^0)$ can be as large as $80\%$ and can suppress significantly the visible $\gamma\gamma$ signal rate, but the latest LHC Higgs data put a strong constraint on it: $Br(h \to \phi^0\phi^0) \leq 30\%$ at $3\sigma$ level; (b) the $p$-value of the LRTH model is around $0.6$, smaller than that of the SM in most of the parameter space and approaches the SM value $0.8$ for a sufficiently large $f$ parameter; (c) the neutral pseudoscalar $\phi^0$ dominantly decay into $b\bar{b}$ and the decay rate $Br(\phi^0\to b\bar{b})$ can be larger than $80\%$ for $m_{\phi^0}\leq 60$ GeV, and the second main decay mode is $\phi^0\to \tau^{+}\tau^{-}$ with a branching ratio about $14\%$; and (d) at the future $e^-e^+$ collider with $\sqrt{s}=250$ GeV, the processes $e^{+}e^{-}\to Zh\to Z(\phi^0\phi^0)\to Z(4b,2b2\tau)$ are promising for discovering such a light pseudoscalar $\phi^0$.

Associated production of the Z boson with a pair of top quarks in the left-right twin Higgs model

In the context of the left-right twin Higgs (LRTH) model, we first examine the effects on the production at the ILC and LHC. Our results show that the cross-sections can be significantly deviated from the standard model predictions and thus provide a good probe for the LRTH model. We also estimate the new production channel, or production, at the LHC. Compared with production, we find that the production can have a sizable production rate when the scale f is not too high. Considering the dominant decay mode , we find that final state has less background than production and may likely be observable at the LHC.

Left-right twin Higgs model confronted with the latest LHC Higgs data

Motivated by the latest LHC Higgs data, we calculate the new physics contributions to the Higgs decay channels of $h\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, $Z\ensuremath{\gamma}$, $\ensuremath{\tau}\ensuremath{\tau}$, $W{W}^{*}$, and $Z{Z}^{*}$ in the left-right twin Higgs (LRTH) model, induced by the loops involving the heavy $T$ quark, the ${W}_{H}$ and ${\ensuremath{\phi}}^{\ifmmode\pm\else\textpm\fi{}}$ bosons that appeared in the LRTH model. We find that (a) for a standard-model-like Higgs boson around 125.5 GeV, the signal rates normalized to the corresponding standard model (SM) predictions are always suppressed when new physics contributions are taken into account and approach the SM predictions for a large scalar parameter $f$; and (b) the LRTH prediction for ${R}_{\ensuremath{\gamma}\ensuremath{\gamma}}$ agrees well with the CMS measurement ${R}_{\ensuremath{\gamma}\ensuremath{\gamma}}=0.77\ifmmode\pm\else\textpm\fi{}0.27$ at $1\ensuremath{\sigma}$ level but differs from the ATLAS result. The forthcoming precision measurement of the diphoton signal at the LHC can be a sensitive probe for the LRTH model.

Single vector-like top partner production in the left-right twin Higgs model at TeV energy eγ colliders

The left-right twin Higgs model contains a new vector-like heavy top quark, which mixes with the SM-like top quark. In this work, we studied the single vector-like top partner production via process e−γ → νeT̄b at the International Linear Collider. We calculated the production cross section at tree level and displayed the relevant differential distributions. The result shows that there will be 125 events produced each year with √s=2 TeV and the integrated luminosity ℒint ≈ 500 fb−1, and the b-quark tagging and the relevant missing energy cut will be helpful to detect this new effect.

Detection of Charged Higgs Bosons in e+e−(γγ) → tb̄φ− Production at the ILC

In the context of the left-right twin Higgs (LRTH) model, we have studied the charged Higgs bosons production processes e+e−(γγ) → tb̄φ− at the International Linear Collider (ILC). It is found that the cross sections of these two processes could reach a few fb with reasonable parameter values. With the yearly integrated luminosity of ℒ = 500fb−1 expected at the ILC, one could collect hundreds up to thousands of charged Higgs events via these two processes. Therefore, our researches in this paper can help us search for charged Higgs bosons, and furthermore, to test the LRTH model.

SINGLE PRODUCTION OF THE GAUGE BOSONS VIA eγ COLLISION AT THE HIGH ENERGY e+e- LINEAR COLLIDERS

The eγ collider is better suited to study single production of the gauge bosons. In this paper, we first consider the contributions of the three-site Higgsless (3SHL) model and the left–right twin Higgs (LRTH) model to the standard model (SM) processes eγ→eZ and eγ→νeW, and then study single production of the new neutral and charged gauge bosons predicted by these two models via eγ collision in the future high energy e+e- linear collider experiments. We find that the correction effects of 3SHL model on the processes eγ→eZ and eγ→νeW might be detected in the future, while this is not the case for the LRTH model. The process eγ→eZ' can give rise to different signatures in the 3SHL and LRTH models and thus can be used to distinguish these two kinds of new physics models at the high energy e+e- linear colliders.

Top quark forward-backward asymmetry and charge asymmetry in the left-right twin Higgs model

In order to explain the Tevatron anomaly of the top quark forward-backward asymmetry ${A}_{\mathrm{FB}}^{t}$ in the left-right twin Higgs model, we choose to give up the lightest neutral particle of $\stackrel{^}{h}$ field as a stable dark matter candidate. Then a new Yukawa interaction for $\stackrel{^}{h}$ is allowed, which can be free from the constraint of same-sign top pair production and contribute sizably to ${A}_{\mathrm{FB}}^{t}$. Considering the constraints from the production rates of the top pair ($t\overline{t}$), the top decay rates, and $t\overline{t}$ invariant mass distribution, we find that this model with such new Yukawa interaction can explain ${A}_{\mathrm{FB}}^{t}$ measured at the Tevatron while satisfying the charge asymmetry ${A}_{C}^{t}$ measured at the LHC. Moreover, this model predicts a strong correlation between ${A}_{C}^{t}$ at the LHC and ${A}_{\mathrm{FB}}^{t}$ at the Tevatron, i.e., ${A}_{C}^{t}$ increases as ${A}_{\mathrm{FB}}^{t}$ increases.

Searches for new neutral gauge boson at the Tevatron and LHC in the left-right twin Higgs model

In the framework of the left-right twin Higgs (LRTH) model, we study the possibilities to detect the new Z′ boson at the Tevatron and LHC. First, using \(p\bar p\) collision data collected by the D0 and CDF II detectors, we find that the LRTH Z′ boson is excluded with masses below 940 GeV. Then we search for signatures of the Z′ boson at the LHC from the analysis of some distributions for \(p\bar p \to \mu ^ + \mu ^ - + X\), such as the number of events, the differential cross section of the dimuon invariant mass, the distributions of the transverse momentum and the forward-backward charge asymmetry. We do our calculation for two typical values of the LHC center of mass energy (7 and 14 TeV). The numerical results show that, by applying convenient cuts on some of the observables, the dimuon invariant mass and final particle pT distributions can reveal the presence of the heavy neutral gauge boson Z′ contribution in the LRTH model.

PRODUCTION OF $ht\bar{t}$ AND $ht\bar{T}$ IN THE LEFT–RIGHT TWIN HIGGS MODEL IN γγ COLLISIONS AT ILC

In the left–right twin Higgs (LRTH) model, we first examine the effects in [Formula: see text] production in γγ collision and find that, in the favorable parameter spaces, the absolute values of the relative correction can be significantly large. We also estimate the new production process [Formula: see text], our results show that its cross-section can reach the level of a few fb for M = 150 GeV . A simply phenomenological analysis is also given for the decay modes T→ϕ+b and T→W+b. As long as the new T-quark is not too heavy, we conclude that this new channel might be used to test the LRTH model in the future ILC experiment.

Single Production of a Heavy T-Quark in the Left-Right Twin Higgs Model at LHeC

In the context of the left-right twin Higgs model, we study single production of a T-quark at the Large Hadron electron Collider based ep and γp colliders, which proceed via the processes e+b → ν̄eT and γb → W−T. For the main decay mode T → φ+b → tb̄b, these two processes mainly transfer to the final states of 3b + l (e or μ) + missing ET and 3b + 2l + missing ET, respectively. With the electron energy Ee = 500 GeV and photon energy Ep=7 TeV, we find that the production rates can reach tens fb when the heavy T—quark mass mT < 600 GeV. A simple phenomenological analysis is also given for the decay mode T → W+b. Our numerical results show that the SM background can be reduced by applying a cut on the transverse momentum of the final b-quark and the invariant mass of Wb. However, such a channel is only useful for a tiny parameter space.

PRODUCTION OF CHARGED HIGGS BOSON ASSOCIATED WITH A W GAUGE BOSON AT THE LHC

Production of charged Higgs boson associated with a W gauge boson at the LHC is mainly induced by the tree-level [Formula: see text] annihilation and the one-loop gg fusion. In the context of the Higgs triplet model (HTM) and the left–right twin Higgs (LRTH) model, we calculate the production cross-section σ of the process pp→H±W∓ and compare our results with those given by supersymmetry (SUSY). We find that, in most of the parameter space of the HTM, the production cross-section σ is smaller than that predicted by the LRTH model or SUSY. The value of σ within the LRTH model is larger or smaller than the SUSY case, which depends on the relevant free parameters.

Associated ZH and WH Production in Left-Right Twin Higgs Model at LHC

At the CERN large hadron collider (LHC), production of the Higgs boson in association with Z or W bosons provides a dramatic experimental signal for detecting the standard model (SM) Higgs boson. In this paper, we consider the contributions of the left-right twin Higgs (LRTH) model to the processes qq̄′ → Z (W) H. Our numerical results show that, in the favorable parameter spaces, the cross sections deviate distinctly from the predictions of the SM. The possible signals of the LRTH model can be detected via these processes at the LHC experiments.

Pair production of right-handed neutrinos in the left-right twin Higgs model at ILC and LHC

In the framework of the left-right twin Higgs model, we study pair production of the right-handed neutrinos at the International Linear Collider (ILC) and the CERN Large Hadron Collider (LHC). Our numerical results show that the production cross section of the process e + e -→ N (tu) is at the level of several tens fb at the ILC. However, the resonance production cross section can be significantly enhanced to the order of pb. The pair production cross section for the right-handed neutrinos is the level of several hundreds of fb at the LHC. In general, pair production of right-handed neutrinos gives rise to 2 l +4 j signal without missing energy. As long as the right-handed neutrinos are not too heavy, we conclude that its pair production might be used to test for the left-right twin Higgs model at the future ILC and LHC experiments.