Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userGaugephobic Higgs Signals at the LHC
87
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The Gaugephobic Higgs model provides an interpolation between three different models of electroweak symmetry breaking: Higgsless models, Randall-Sundrum models, and the Standard Model. At parameter points between the extremes, Standard Model Higgs signals are present at reduced rates, and Higgsless Kaluza-Klein excitations are present with shifted masses and couplings, as well as signals from exotic quarks necessary to protect the Zbb coupling. Using a new implementation of the model in SHERPA, we show the LHC signals which differentiate the generic Gaugephobic Higgs model from its limiting cases. These are all signals involving a Higgs coupling to a Kaluza-Klein gauge boson or quark. We identify the clean signal $p p to W^(i) to W H$ mediated by a Kaluza-Klein W, which can be present at large rates and is enhanced for even Kaluza-Klein numbers. Due to the very hard lepton coming from the W decay, this signature has little background, and provides a better discovery channel for the Higgs than any of the Standard Model modes, over its entire mass range. A Higgs radiated from new heavy quarks also has large rates, but is much less promising due to very high multiplicity final states.
rate research
Read More
We consider an extension of the Standard Model involving a singlet Higgs and down type vector-like quarks in the light of the current LHC Higgs data. For a good range of the parameters of the Higgs potential, and a mass range for the heavy vector-like quark, we find that the singlet heavy Higgs arising from the production and decay of the vector-like quarks give rise to (2b~4t) signal. The subsequent decay of the top quarks to $b W^{+}$ give rise to a final state with six b quarks, two same-sign charged leptons and missing transverse momenta with observable cross-sections at the 14 TeV run of the Large Hadron Collider. The Standard Model background for such a final state is practically negligible.
Warped models with the Higgs in the bulk can generate light Kaluza-Klein (KK) Higgs modes consistent with the electroweak precision analysis. The first KK mode of the Higgs (h_{1}) could lie in the 1-2 TeV range in the models with a bulk custodial symmetry. We find that the h_{1} is gaugephobic and decays dominantly into a tbar{t} pair. We also discuss the search strategy for h_{1} decaying to tbar{t} at the Large Hadron Collider. We used substructure tools to suppress the large QCD background associated with this channel. We find that h_{1} can be probed at the LHC run-2 with an integrated luminosity of 300 fb^{-1}.
We study the LHC phenomenology of a general class of Private Higgs (PH) models, in which fermions obtain their masses from their own Higgs doublets with $op(1)$ Yukawa couplings, and the mass hierarchy is translated into a dynamical chain of vacuum expectation values. This is accomplished by introducing a number of light gauge-singlet scalars, the darkons, some of which could play the role of dark matter. These models allow for substantial modifications to the decays of the lightest Higgs boson, for instance through mixing with TeV-scale PH fields and light darkons: the simplest version of the model predicts the ratios of partial widths to satisfy $G(h to VV^*)_{text{PH}}/G(h to VV^*)_{text{SM}} approx G(h to gg)_{text{PH}}/G(h to gg)_{text{SM}} leq 1$ and $G(h to bbar b)_{text{PH}}/G(h to bbar b)_{text{SM}} sim op(1)$, where the inequalities are saturated only in the absence of Higgs mixing with light darkons. An extension of the model proposed previously for generating nonzero neutrino masses can also contribute substantially to $h to gg$ without violating electroweak precision constraints. If the Higgs coupling to fermions is found to deviate from the Standard Model (SM) expectation, then the PH model may be a viable candidate for extending the SM.
We investigate the possible collider signatures of a new Higgs in simple extensions of the Standard Model where baryon number is a local symmetry spontaneously broken at the low scale. We refer to this new Higgs as Baryonic Higgs. This Higgs has peculiar properties since it can decay into all Standard Model particles, the leptophobic gauge boson, and the vector-like quarks present in these theories to ensure anomaly cancellation. We investigate in detail the constraints from the $gamma gamma$, $Z gamma$, $Z Z$, and $W W$ searches at the Large Hadron Collider, needed to find a lower bound on the scale at which baryon number is spontaneously broken. The di-photon channel turns out to be a very sensitive probe in the case of small scalar mixing and can severely constrain the baryonic scale. We also study the properties of the leptophobic gauge boson in order to understand the testability of these theories at the LHC.
Recent excesses across different search modes of the collaborations at the LHC seem to indicate the presence of a Higgs-like scalar particle at 125 GeV. Using the current data sets, we review and update analyses addressing the extent to which this state is compatible with the Standard Model, and provide two contextual answers for how it might instead fit into alternative scenarios with enlarged electroweak symmetry breaking sectors.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
