This report summarises the physics opportunities for the study of Higgs bosons and the dynamics of electroweak symmetry breaking at the 100 TeV pp collider.

By solving the Einstein equations of the graviton coupling with a real scalar dilaton field, we establish a general framework to self-consistently solve the geometric background with black-hole for any given phenomenological holographic models. In this framwork, we solve the black-hole background, the corresponding dilaon field and the dilaton potential for the deformed AdS 5 model with a positive/negative quadratic correction. We systematically investigate the thermodynamical properties of the deformed AdS 5 model with a positive and negative quadratic correction, respectively, and compare with lattice QCD on the results of the equation of state, the heavy quark potential, the Polyakov loop and the spatial Wilson loop. We find that the bulk thermodynamical properties are not sensitive to the sign of the quadratic correction, and the results of both deformed holographic QCD models agree well with lattice QCD result for pure SU(3) gauge theory. However, the results from loop operators favor a positive quadratic correction, which agree well with lattice QCD result. Especially, the result from the Polyakov loop excludes the model with a negative quadratic correction in the warp factor of AdS 5 .

In this paper we analyze the process B s → ℓ + ℓ − in a model II 2HDM and MSSM. All the leading terms of Wilson coefficients relevant to the process are given in the large tanβ limit. It is shown that the decay width for B s → ℓ + ℓ − depends on all parameters except m A 0 in the 2HDM. The branching ratio of B s → µ + µ − can reach its experimental bound in some large tanβ regions of the parameter space in MSSM because the amplitude increases like tan 3 β in the regions. For l=τ , the branching ratio can even reach 10 −4 in the regions. Therefore, the experimental measurements of leptonic decays of B s could put a constraint on the contributions of neutral Higgs bosons and consequently the parameter space in MSSM.

The dominance of h → ηη decay mode for the intermediate mass Higgs boson is highly motivated to solve the little hierarchy problem and to ease the tension with the precision data. However, the discovery modes for m h < ∼ 150 GeV, h → γγ and W/Zh → (ℓν/ℓ l)(b b), will be substantially affected. In this Letter, we show that h → ηη → 4b is complementary and we can use this decay mode to detect the intermediate Higgs boson at the LHC, via W h and Zh production. Requiring at least one charged lepton and 4 B-tags in the final state, we can identify a clean Higgs boson signal for m h < ∼ 150 GeV with a high significance and with a full Higgs mass reconstruction. We use the next-to-minimal supersymmetric standard model and the simplest little Higgs model for illustration.

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The quartic self-coupling of the Standard Model Higgs boson can only be measured by observing the triple-Higgs production process, but it is challenging for the LHC Run 2 or ILC at a few TeV because of its extremely small production rate. In this paper, we present a detailed MC simulation study of the triple-Higgs production through gluon fusion at a 100 TeV hadron collider and explore the feasibility of observing this production mode. We focus on the decay channel HHH → bbbbγγ, investigating detector effects and optimizing the kinematic cuts to discriminate the signal from the backgrounds. Our study shows that in order to observe the Standard Model triple-Higgs signal, the integrated luminosity of a 100 TeV hadron collider should be greater than 1.8 × 10 4 ab −1 . We also explore the dependence of the cross section upon the trilinear (λ 3 ) and quartic (λ 4 ) self-couplings of the Higgs. We find that, through a search in the triple Higgs production, the parameters λ 3 and λ 4 can be restricted to the ranges [−1, 5] and [−20, 30], respectively. We also examine how new physics can change the production rate of triple-Higgs events. For example, in the singlet extension of the Standard Model, we find that the triple-Higgs production rate can be increased by a factor of O(10).

We stude the holographic QCD model which contains a quadratic term −σz 2 and a logarithmic term −c 0 log[(z IR − z)/z IR ] with an explicit infrared cut-off z IR in the deformed AdS 5 warp factor. We investigate the heavy quark potential for three cases, i.e, with only quadratic correction, with both quadratic and logarithmic corrections and with only logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation, and investigate the corresponding beta function in the Gürsoy -Kiritsis-Nitti (GKN) framework. Our studies show that in the case with only quadratic correction, a negative σ or the Andreev-Zakharov model is favored to fit the heavy quark potential and to produce the QCD beta-function at 2-loop level, however, the dilaton potential is unbounded in infrared regime. One interesting observing for the case of positive σ, or the soft-wall AdS 5 model is that the corresponding beta-function exists an infrared fixed point. In the case with only logarithmic correction, the heavy quark Cornell potential can be fitted very well, the corresponding beta-function agrees with the QCD beta-function at 2-loop level reasonably well, and the dilaton potential is bounded from below in infrared. At the end, we propose a more compact model which has only logarithmic correction in the deformed warp factor and has less free parameters.

We formulate an extended linear σ model of a quarkonia nonet and a tetraquark nonet as well as a complex iso-singlet (glueball) by virtue of chiral symmetry SUL(3) × SUR(3) and UA(1) symmetry. In the linear realization formalism, we study the mass spectra and components of the low-lying scalars and pseudo scalars in this model. The mass matrices for physical staes are obtained and the glueball candidates are examined. We find that the model can accommodate the mass spectra of low-lying states quite well. Our fits indicate that the most glueball like scalar should be 2 GeV or higher while the glueball pseudoscalar is η(1756). We also examine the parameter region where the lightest iso-scalar f0(600) can be the glueball and quarkonia dominant but find such a parameter region may be confronted with the problem of the unbounded vacuum from below.PACS numbers: I. INTRODUCTIONThe pseudoscalar, vector and axial-vector as well as tensor mesons of light quarks have been well-understood in the naive quark model in terms of the chiral symmetry. Despite of its success, the naive quark model can not explain the scalar meson sector, which have the same quantum numbers as the vacuum. There are about 19 states which are twice more than the expectedqq nonet as in vector and tensor sectors, while the mass and decay pattern of these low-lying scalars are different from the expectation of the naive quark model. To understand the nature of these scalars has been the focus of recent studies e.g. see Refs. [1][2][3][4] and references therein.Among the low-lying scalar mesons, the lightest scalar f 0 (600) or σ attracts a lot of interests. It is widely believed that f 0 (600) is like the Higgs boson which plays a crucial role in the spontaneous chiral symmetry breaking. Confirmation of existence of the elusive f 0 (600) from ππ scattering processes settles down a controversy last for more than a few decades [2,5]. The πK scattering [6] and analysis from D decay D + → K − π + π − [7] revealed that κ should also exist. BES II also found such a κ like structure in J/Ψ decays [8]. Combined with the well determined sharp resonances, i.e. isoscalar f 0 (980) and isotriplet a(980) from ππ and πη as well as KK scattering processes, now it is accepted in literature that these low-lying scalar mesons (say less than 1 GeV) can be cast into a chiral nonet. The next important issue is what is the nature of this nonet.There are a couple of viewpoints on the nature of this nonet. For example,the tetraquark model [9] can explain the mass hierarchy and decay pattern of this nonet quite successfully and is further supported from other experimental data, like the photon-photon collision data, which prefer the tetraquark interpretation for the lowest scalar meson nonet [10] (where it is demonstrated that f 0 (980) should be a tetraquark dominant state with great details). An alternative interpretation is that this nonet is bound state of the meson-meson molecule [11]. In any way, this nonet challenges a self-consistent interpretation in the naive quark mod...