In the little higgs scenario, several coupling constants are related to each other to guarantee the stability of the higgs boson mass at one-loop level. This relation is called the little higgs mechanism. We discuss how accurately the relation can be tested at future $e^+e^-$ colliders, with especially focusing on the top sector of the scenario using a method of effective lagrangian. In order to test the mechanism, it is important to measure the Yukawa coupling of the top partner. Higgs associated and threshold productions of the top partner are found to be the best processes for this purpose.
Theoretical overview on phenomenology of Higgs boson and SUSY Higgs boson at a future linear collider experiment is given as a Higgs and SUSY Higgs working group summary report for LCWS 2000.
We discuss the importance of being able to detect Higgs-to-Higgs-pair decays in the context of the Next-to-Minimal Supersymmetric Model (NMSSM) and demonstrate the excellent capabilities of a photon collider for this purpose.
The manner in which the parameters of a two-Higgs-doublet model can be chosen so that no Higgs boson is discovered at a $\sqrt{s}\leq 800\gev$ $\epem$ collider, while maintaining consistency with current precision electroweak measurements, is described. The importance of a Giga-$Z$ factory and higher collider energies for such a scenario is emphasized.
Here we review potential of the Photon Collider for study of Higgs physics after discovery of the SM-like Higgs boson at the LHC. In general, the Photon Collider will fill in the LHC and ILC results, giving in some cases unique information which cannot be obtained at other machines.
We review the role of a muon collider in the study of Higgs bosons via production in the s-channel. Very precise measurements of a Standard Model-like Higgs boson mass and total width can be performed, and may lead to a discrimination between a Standard Model Higgs boson and the light Higgs boson of the minimal supersymmetric theory. The heavier Higgs bosons from a supersymmetric theory or an exotic Higgs sector can be studied in the s-channel. A muon collider may play a crucial role in separating the overlapping signals for two heavy nearly degenerate Higgs bosons, and may play an important r…
The theoretical status of Higgs boson and supersymmetric particle production at hadron colliders is reviewed with particular emphasis on recent results and open problems.
High-energy $γγ$ colliders constitute a potential running mode of future $e^+ e^-$ colliders such as the ILC and CLIC. We study the sensitivity of a high-energy $γγ$ collider to the Higgs portal scenario to a hidden sector above the invisible Higgs decay threshold. We show that such $γγ$ collisions could allow to probe the existence of dark sectors through the Higgs portal comparatively more precisely than any other planned collider facility, from the unique combination of sizable cross-section with clean final state and collider environment. In addition, this search could cover the singlet Hi…
This letter reviews the potential of a high luminosity e+e- linear collider (LC) in the precision study of the Higgs boson profile. The complementarity with the Large Hadron Collider (LHC) Higgs physics program is briefly discussed.
This Thesis is devoted to the study of the phenomenology of the Higgs sector of the minimal $B-L$ extension of the Standard Model at present and future colliders. Firstly, the motivations that call for the minimal $B-L$ extension are summarised. In addition, the model is analysed in its salient parts. Moreover, a detailed review of the phenomenological allowed Higgs sector parameter space is given. Finally, a complete survey of the distinctive Higgs boson signatures of the model at both the Large Hadron Collider and the future linear colliders is presented.
Pseudoscalar and charged Higgs bosons production in the processes $μ^+ μ^-\to P^0_i Z^0$, $μ^+μ^- \to H^{\pm}W^{\mp}$ within the models with several Higgs doublets and singlets is considered.
To provide context for discussions of experiments at future muon colliders, I survey what is known and what will be known about the top quark and the Higgs boson from experiments at hadron colliders.
I summarize the prospects for discovering and studying the properties of Higgs particles at future high-energy and high-luminosity $e^+e^-$ linear colliders. I will focus on the Higgs particle of the Standard Model and the Higgs bosons predicted by Supersymmetric theories.
We present a comprehensive analysis on the MSSM Higgs sector CP violation at photon colliders including the chargino contributions as well as the contributions of other charged particles. The chargino loop contributions can be important for the would-be CP odd Higgs production at photon colliders. Polarization asymmetries are indispensable in determining the CP properties of neutral Higgs bosons.
We investigate the potential of single Higgs boson production at the LHC and at egamma mode of future linear electron-positron collider to probe non-standard HZgamma and Hgammagamma couplings. We consider the semi-elastic production process pp-> p gamma p-> pHqX at the LHC where q represents the quarks and X represents the remnants of one of the initial protons. We also study the single Higgs production through gamma e-> He in the egamma collision at the future linear collider. We perform a model-independent analysis and obtain the sensitivity bounds on the non-standard Higgs couplings for bot…
Assuming that a Higgs sector is responsible for electroweak symmetry breaking, we attempt to address two important questions: How much better precision are various measurements of Higgs boson properties at a future linear collider than at the LHC? What can a future linear collider do for Higgs physics that the LHC cannot?
We consider the production of singly charged Higgs bosons in the Higgs triplet and two Higgs doublet models. We evaluate the cross sections for the pair production and the single production of charged higgses at linear collider. The decay modes of $H^+$ and the Standard Model backgrounds are considered. We analyze the possibilities to differentiate between triplet and two Higgs doublet models.
I briefly review the Higgs sector in the Standard Model. After summarizing the properties of the Higgs boson, I will discuss the prospects for discovering this particle at the present colliders LEP2 and Tevatron and at the next generation colliders LHC and a high-energy $e^+e^-$ linear collider. The possibilities of studying the properties of the Higgs particle will be then summarized. [Contribution to the European Network Workshop "Tests of the Electroweak Symmetry Breaking}, Ouranoupolis, Greece, May 1997.]
The production of single and doubly charged Higgs bosons associated with standard model gauge boson $Z_L$ in $e^{+}e^{-}$ colliders are examined. The sensitivity of these processes on the littlest Higgs model parameters in the range of compatibility with electroweak precision observables are analyzed. The possibility of detecting lepton flavor violation processes are also discussed.
Methods for extracting Higgs boson signals at a 1 TeV center-of-mass energy e+e- linear collider are described. In addition, estimates are given for the accuracy with which branching fractions can be measured for Higgs boson decays to bb, WW, gluon-gluon, and gamma-gamma.
The production of triple Higgs $(H^+H^-H^0)$, $(H^+H^-h^0)$ and pair wise charged Higgs boson $(H^+H^-)$ is studied in the context of future linear colliders within the Two-Higgs Doublet Model (2HDM) type II. The aim is to compare sources of charged Higgs pair through the above processes, i.e., double and triple Higgs production. Cross-sections are calculated at the leading order in 2HDM type II and Minimal Supersymmetric Standard Model (MSSM). Several orders of magnitude ($\sim 10^{4}$) enhancement is observed in 2HDM compared to MSSM, while no sizable enhancement is seen in muon collider ver…
We examine the potential for detecting and studying Higgs bosons at a photon-photon collider facility associated with a future linear collider. Our study incorporates realistic $\gam\gam$ luminosity spectra based on the most probable available laser technology. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson; b) the heavy MSSM Higgs bosons; c) a Higgs boson with no $WW/ZZ$ couplings from a general two Higgs doublet model.
The little Higgs idea is a new way to solve the little hierarchy problem by protecting the Higgs mass from quadratically divergent one-loop corrections. In this talk I describe the phenomenology of one particular realization of the little Higgs idea: the "Littlest Higgs" model.
In this study, Higgs production processes, Higgsstrahlung and vector boson (W and Z) fusion processes, were investigated for four different future lepton colliders (CEPC, ILC, CLIC, and FCC-ee). The cross sections for each production process and corresponding backgrounds were calculated considering the ISR and beamstrahlung effects. Various cuts and the b-tagging method were used to reduce the background. Finally, the number of events for each collider was determined, and significance calculations were performed. In our calculations, high event numbers were obtained for all four colliders for …
We calculate Higgs production cross sections at a muon collider in the Two Higgs Doublet Model of type II. The most interesting productions channels are mu^- mu^+ --> h^0 Z^0, H^0 Z^0, H^- H^+, A^0 Z^0 and H^{-/+} W^{+/-}. The last channel is compared with the production processes p pbar --> H^{-/+} W^{+/-} X and p p --> H^{-/+} W^{+/-} X at the Tevatron and LHC energies, respectively, for large values of tan(beta).
We present here the results for Higgs and Supersymmetry prospective searches at the Large Hadron Collider. We show that for one year at high luminosity, Standard Model and MSSM Higgs should be observed within the theoretically expected mass range. MSUGRA and restricted phenomenological MSSM searches lead to discovery of up to 2.5 TeV squarks and gluinos.
We investigate the influence of scalar gauge singlets on Higgs signals at a linear collider. These lead to a large invisible decay width of the Higgs. We find that for high luminosities ($500-1000 fb^{-1}$) one can essentially cover the allowed parameter range of the model.
The quartic Higgs self-coupling is the final measurement in the Higgs potential needed to fully understand electroweak symmetry breaking. None of the present or future colliders are known to be able to determine this parameter. We study the chances of measuring the quartic self-coupling at hadron colliders in general and at the VLHC in particular. We find the prospects challenging.
In this review we demonstrate physics potential of a photon linear collider by studying the neutral Higgs-boson sector of the MSSM in which interesting CP-violating Higgs mixing could arise via radiative corrections.
Little Higgs theory naturally predicts a light Higgs boson whose most important discovery channel at the LHC is the di-photon signal $pp\to h\to γγ$. In this work we perform a comparative study for this signal in some typical little Higgs models, namely the littlest Higgs model (LH), two littlest Higgs models with T-parity (named LHT-I and LHT-II) and the simplest little Higgs modes (SLH). We find that compared with the Standard Model prediction, the di-photon signal rate is always suppressed and the suppression extent can be quite different for different models. The suppression is mild ($\lsi…
The discovery of the Higgs particle at 125 GeV is demanding a detailed knowledge of the properties of this fundamental component of the Standard Model. To that aim various proposals of electron and muon colliders have been put forward for precision studies of the partial widths of the various decay channels. It is shown that in the case of a Higgs factory through a muon collider, sizeable radiative effects - of order of 50% - must be carefully taken into account for a precise measurement of the leptonic and total widths of the Higgs particle. Similar effects do not apply in the case of Higgs p…
The theoretical structure of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM) is briefly described. An outline of Higgs phenomenology at future lepton colliders is presented, and some opportunities for probing the physics of the MSSM Higgs sector at an e-e- collider are considered.
This paper reviews the potential of a high luminosity e+e- linear collider (LC) in the precision study of the Higgs boson profile. The complementarity of the linear collider data with that from the LHC is also discussed together with a comparison with a muon collider.
In this talk, I discuss some aspects of Higgs searches at future colliders, particularly comparing and contrasting the capabilities of LHC and Next Linear Collider (NLC), including the aspects of Higgs searches in supersymmetric theories. After this, I will discuss how the search and study of sparticles other than the Higgs can give information about the parameters of the Minimal Supersymmetric Standard Model (MSSM).
In this paper, we review the role of a multi-TeV $e^+e^-$ linear collider to complete the mapping of the Higgs boson profile and studying heavier bosons in extended scenarios with more than one Higgs doublet.
We give a brief review of recent developments in non-supersymmetric models for electroweak symmetry breaking, including little Higgs, composite Higgs and Higgsless theories. The new ideas such as extra dimensions, AdS/CFT correspondence, dimension-deconstruction, and collective symmetry breaking provide us new tools to construct new models. They also allow some old ideas to be revived and implemented in these new models.
We calculate the cross section of the lightest Higgs boson pair production at the Photon Linear Collider in the two Higgs doublet model. We focus on the scenario in which the lightest Higgs boson has the standard model like couplings to gauge bosons. We take into account the one-loop correction to the $hhh$ coupling as well as additional one-loop diagrams due to charged bosons to the $γγ\to hh$ helicity amplitudes. We discuss the impact of these corrections on the $hhh$ coupling measurement at the Photon Linear Collider.
We study the effects of heavy Higgs bosons on the top-pair production process at photon linear colliders. The interference patterns between the resonant Higgs-production amplitudes and the continuum QED amplitudes are examined. The patterns tell us not only the CP nature of the Higgs bosons but also the phase of the $γγ$--Higgs vertex which gives new information about the Higgs couplings to new charged particles.
In this note we analyse the prospects of a future electron-positron collider in testing a particular realisation of a composite Higgs model encompassing partial compositeness, namely, the 4-Dimensional Composite Higgs Model. We study the main Higgs production channels for three possible energy stages and different luminosity options of such a machine and confront our results to the expected experimental accuracies in the various Higgs decay channels accessible herein and, for comparison, also at the Large Hadron Collider.
The threshold dependence and angular correlations of Higgs-strahlung in e+e- collisions can be used to demonstrate the spinless nature of the Standard Model Higgs boson. This method, and its possible extention to heavy neutral MSSM Higgs bosons, is discussed.
The SU(3)$_L\otimesU(1)_N$ electroweak model predicts new Higgs bosons beyond the one of the standard model. In this work we investigate the signature and production of doubly charged Higgs bosons in the $e^-e^+$ International Linear Collider and in the CERN Linear Collider. We compute the branching ratios for the doubly charged gauge bosons of the model.
In order to verify the Higgs mechanism experimentally, the Higgs self-couplings have to be probed. These couplings allow the reconstruction of the characteristic Higgs potential responsible for the electroweak symmetry breaking. The couplings are accessible in a variety of multiple Higgs production processes. The theoretical analysis including the most relevant channels for the production of neutral Higgs boson pairs at high-energy and high-luminosity $e^+e^-$ linear colliders will be presented in this note.
The next generation electron-positron colliders are designed for precision studies of the Standard Model and its extensions, in particular in the Higgs sector. We consider the potential for discovery of composite Higgs models in Higgs pair production through photon collisions. This process is loop-generated, thus it provides access to all Higgs couplings and can show new physics effects in polarized and unpolarized cross-sections starting at relatively low collider energies. It is, therefore, relevant for all electron-positron colliders planned or in preparation. Sizeable deviations from the S…
We consider triple Higgs boson production at a future 100 TeV proton-proton collider. We perform a survey of viable final states and compare and contrast triple production to Higgs boson pair production. Focussing on the $hhh \rightarrow (b\bar{b}) (b\bar{b}) (γγ)$ final state, we construct a baseline analysis for the Standard Model scenario and simple deformations, demonstrating that the process merits investigation in the high-luminosity phase of the future collider as a new probe of the self-coupling sector of the Higgs boson.
In this paper, charged Higgs pair production through $\ell^+ \ell^- \rightarrow H^+ H^-$ where $\ell = e$ or $μ$, is studied within the framework of a general Two Higgs Doublet Model (2HDM). The analysis is relevant to a future $e^+e^-$ or $μ^+μ^-$ collider operating at center of mass energy of $\sqrt{s}=500$ GeV. Two different scenarios of small and large $α$ values is studied. Here $α$ is the parameter which diagonalizes the neutral CP-even Higgs boson mass matrix. Within the Minimal Supersymmetric Standard Model (MSSM), cross section of this process is almost the same at $e^+e^-$ and $μ^+μ^…
In this note we present a review of the little Higgs models that stabilize the electroweak by realizing the Standard Model Higgs as a pseudo-Goldstone boson.
We have calculated the cross section of the process $e^+e^- \to W^{\pm}H^{\mp}$ at the linear collider in the supersymmetrical two-higgs-doublet model. We find that the cross section decreases rapidly with the increment of $\tanβ$, and which can reach almost 1 fb for the favorable parameters.
We study the effect of heavy neutral Higgs bosons on the top pair production process at photon linear colliders.The interference patterns betwenn the resonant Higgs production amplitudes and the continuum QED amplitudes are examined. The patterns are sensitive to the phase of the photon-photon-Higgs vertex which is a good probe of new charged particles.
Assuming perturbativity up to a high energy scale $\sim 10^{16}$ GeV, we demonstrate that a future $e^+e^-$ linear collider operating at $\sqrt{s} =$ 500 GeV with $\int{\cal L}=$ 500 fb$^{-1}$ per year (such as the recently proposed TESLA facility) will detect a Higgs boson signal regardless of the complexity of the Higgs sector and of how the Higgs bosons decay.
In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein graviton and graviscalar interference with Higgs boson production amplitudes are computed at linear colliders and Higgs factories. The interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Plank scale M_D and the number of extra dimensions δ. We find that, for M_D ~ 1 TeV and δ=2, effects of the order of a few percent could be detected for heavy Higgs bosons (m_H…
We investigate Higgs pair production at proton-proton colliders, with emphasis on the gluon fusion channel at the HL-LHC. We study the behaviour of the leading order matrix element using exact computation of quark loops and infinite quark mass approximation. We analyse di-Higgs kinematics in search for phase space regions where the contribution of Higgs self-coupling to SM Higgs pair production is enhanced. We discuss how non-SM values of the Higgs trilinear coupling may affect the kinematics of the Higgs pair.
We examine the sensitivity of $e γ$ colliders (based on $e^+ e^-$ linear colliders of c.m. energy 500 GeV) to the anomalous couplings of the Higgs to W-bosons via the process $e^- γ\longrightarrow νW H$. This has the advantage over $e^+ e^-$ collider in being able to dissociate WWH vertex from ZZH. We are able to construct several dynamical variables which may be used to constrain vrious couplings in the WWH vertex.
Many of the new physics models predicts a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at the FCC-hh collider. With an integrated luminosity of 500 fb$^{-1}$ at very high energy frontier, we obtain a significant coverage of the parameter space and dist…
