Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userInverse Amplitude Method for Perturbative Electroweak Symmetry Breaking Sector: The Singlet Higgs Portal as a Study Case
70
0
0.0
(
0
)
Authors
Tyler Corbett
Ask ChatGPT about the research
No Arabic abstract
We explore the use of the Inverse Amplitude Method for unitarization of scattering amplitudes to derive the existence and properties of possible new heavy states associated with perturbative extensions of the electroweak breaking sector of the Standard Model starting from the low energy effective theory. We use a toy effective theory generated by integrating out a heavy singlet scalar and compare the pole mass and width of the unitarized amplitudes with those of the original model. Our results show that the Inverse Amplitude Method reproduces correctly the singlet mass up to factors of O(1-3), but its width is overestimated.
rate research
Read More
We consider generation of dark matter mass via radiative electroweak symmetry breaking in an extension of the conformal Standard Model containing a singlet scalar field with a Higgs portal interaction. Generating the mass from a sequential process of radiative electroweak symmetry breaking followed by a conventional Higgs mechanism can account for less than 35% of the cosmological dark matter abundance for dark matter mass $M_s>80 GeV$. However in a dynamical approach where both Higgs and scalar singlet masses are generated via radiative electroweak symmetry breaking we obtain much higher levels of dark matter abundance. At one-loop level we find abundances of 10%--100% with $106 GeV<M_s<120 GeV$. However, when the higher-order effects needed for consistency with a $125 GeV$ Higgs mass are estimated, the abundance becomes 10%--80% for $80 GeV<M_s<96 GeV$, representing a significant decrease in the dark matter mass. The dynamical approach also predicts a small scalar-singlet self-coupling, providing a natural explanation for the astrophysical observations that place upper bounds on dark matter self-interaction. The predictions in all three approaches are within the $M_s>80 GeV$ detection region of the next generation XENON experiment.
We propose a new dynamical relaxation mechanism of the little hierarchy problem, based on a singlet extension of the minimal supersymmetric standard model (MSSM). In this scenario, the small soft mass parameter of an MSSM singlet is responsible for the electroweak symmetry breaking and the non-zero Higgs vacuum expectation value, whereas the effect of the large soft mass parameter of the Higgs boson, -m_{h_u}^2 is dynamically compensated by a flat direction of the MSSM singlets. The small singlets soft mass and the Z boson mass can be protected, even if the stop mass is heavier than 10 or 20 TeV, since the gravity-mediated supersymmetry breaking effects and the relevant Yukawa couplings are relatively small. A focus point of the singlets soft mass parameter can emerge around the stop mass scale, and so various fine-tuning measures can reduce well below 100. Due to the relatively large gauge-mediated effects, the MSSM superpartners are much heavier than the experimental bounds, and the unwanted flavor changing processes are adequately suppressed.
In this review, we discuss methods of parsing direct and indirect information from collider experiments regarding the Higgs boson and describe simple ways in which experimental likelihoods can be consistently reconstructed and interfaced with model predictions in pertinent parameter spaces. Ultimately these methods are used to constrain a five-dimensional parameter space describing a model-independent framework for electroweak symmetry breaking. We review prevalent scenarios for extending the electroweak symmetry breaking sector relative to the Standard Model and emphasize their predictions for nonstandard Higgs phenomenology that could be observed in LHC data if naturalness is realized in particular ways. Specifically we identify how measurements of Higgs couplings can be used to imply the existence of new physics at particular scales within various contexts, highlighting some parameter spaces of interest in order to give examples of how the data surrounding the new state can most effectively be used to constrain specific models of weak scale physics.
Models with extended Higgs boson sectors are of prime importance for investigating the mechanism of electroweak symmetry breaking for Higgs decays into four fermions and for Higgs-production in association with a vector bosons. In the framework of the Two-Higgs-Doublet Model using two scenarios obtained from the experimental measurements we presented next-to-leading-order results on the four-fermion decays of light CP-even Higgs boson, $h rightarrow 4f$. With the help of Monte Carlo program Prophecy 4f 3.0, we calculated the values $Gamma= Gamma_{EW} /left(Gamma_{EW}+Gamma_{SM}right)$ and $Gamma= Gamma_{EW+QCD} /left(Gamma_{EW+QCD}+Gamma_{SM}right)$ for Higgs boson decay channels $ H rightarrow u_{mu} overline{mu} e overline{ u_e}$, $mu overline{mu} e overline{e}$, $e overline{e} e overline{e}$. We didnt find significant difference when accounting QCD corrections to EW processes in the decay modes of Higgs boson. Using computer programs Pythia 8.2 and FeynHiggs we calculated the following values: $sigma(VBH)BR(Hrightarrow ZZ)$ and $sigma(VBF)BR(H rightarrow WW)$ for VBF production processes, $sigma(ggH)BR(H rightarrow WW)$ and $sigma(ggH)BR(H rightarrow ZZ)$ for gluon fusion production process at 13 and 14 TeV and found good agreement with experimental data.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
