Probing the Higgs sector of Y=0Y=0 Higgs Triplet Model at LHC

In this paper, we investigate the Higgs Triplet Model with hypercharge $Y_{\Delta}=0$ (HTM0), an extension of the Standard model, caracterised by a more involved scalar spectrum consisting of two CP even Higgs $h^0, H^0$ and two charged Higgs bosons $H^\pm$. We first show that the parameter space of HTM0, usually delimited by combined constraints originating from unitarity and BFB as well as experimental limits from LEP and LHC, is severely reduced when the modified Veltman conditions at one loop are also imposed. Then, we perform an rigorous analysis of Higgs decays either when $h^0$ is the SM-like or when the heaviest neutral Higgs $H^0$ is identified to the observed $125$ GeV Higgs boson at LHC. In these scenarios, we perform an extensive parameter scan, in the lower part of the scalar mass spectrum, with a particular focus on the Higgs to Higgs decay modes $H^0 \to h^0h^0, H^\pm\,H^\mp$ leading predominantly to invisible Higgs decays. Finally, we also study the scenario where $h^0, H^0$ are mass degenerate. We thus find that consistency with LHC signal strengths favours a light charged Higgs with a mass about $176\sim178$ GeV. Our analysis shows that the diphoton Higgs decay mode and $H \to Z \gamma$ are not always positively correlated as claimed in a previous study. Anti-correlation is rather seen in the scenario where $h$ is SM like, while correlation is sensitive to the sign of the potential parameter $\lambda$ when $H$ is identified to $125$ GeV Higgs.Comment: 33 pages, 12 figures, 1 table, references added, version to be published in Eur. Phys. J.

Is Supersymmetric Quantum Mechanics compatible with Duality

Supersymmetry applied to quantum mechanics has given new insights in various topics of theoretical physics like analytically solvable potentials, WKB approximation or KdV solitons. Duality plays a central role in many supersymmetric theories such as Yang-Mills theories or strings models. We investigate the possible existence of some duality within supersymmetric quantum mechanics.Comment: 15 pages, 3 figure

Charginos and Neutralinos Production at 3-3-1 Supersymmetric Model in e−e−e^-e^- Scattering

The goal of this article is to derive the Feynman rules involving charginos, neutralinos, double charged gauge bosons and sleptons in a 3-3-1 supersymmetric model. Using these Feynman rules we will calculate the production of a double charged chargino with a neutralino and also the production of a pair of single charged charginos, both in an electron- electron $e^-e^-$ process.Comment: 18 pages, 8 figures, 2 table

Electroweak corrections to decays involving a charged Higgs boson

We present complete one-loop radiative corrections to the decay rate of a top quark into a charged Higgs boson and a bottom quark, and for the decay of a charged Higgs boson into leptons. The results are discussed in the framework of the two Higgs boson extension of the Standard Model suggested by supersymmetry. The effect of electroweak corrections after exclusion of universal corrections $\Delta r$ is found to decrease the partial width of the top quark typically by 5%.Comment: 16 pages plus 11 figures available from the author upon request, latex, Alberta Thy-29-9

Associated production of H^{\pm} and W^{\mp} in high-energy e+e- collisions in the Minimal Supersymmetric Standard Model

We study the associated production of the charged Higgs boson and W^{\pm} gauge boson in high energy e+e- collisions in the Minimal Supersymmetric Standard Model (MSSM). This associated production, which first arises at the one loop level, offers the possibility of producing the charged Higgs boson at the e+e- collider with mass more than half the center-of-mass energy, when the charged Higgs pair production is kinematically forbidden. We present analytic and numerical results for the cross section for e+e- --> W+ H- in the full MSSM, taking into account the previously uncalculated contributions from supersymmetric (SUSY) particles. We find that the contributions of the SUSY particles enhance the cross section over most of SUSY parameter space, especially when the SUSY particles are light, ~200 GeV. With favorable SUSY parameters, at small tan beta, this process can yield more than ten W^{\pm}H^{\mp} events for m_{H^{\pm}} <~ 350 GeV in 500 fb-1 at a 500 GeV e+e- collider, or m_{H^{\pm}} <~ 600 GeV in 1000 fb-1 at a 1000 GeV collider. 80% left-handed polarization of the e- beam improves these reaches to m_{H^{\pm}} <~ 375 GeV and m_{H^{\pm}} <~ 670 GeV, respectively.Comment: v2: 21 pages, 9 figures, comments on Higgs search bounds and new references added, and minor changes; v3: 23 pages, 11 figures, review of literature moved from introduction to new Sec.5 and 2 plots added, references added, typos corrected; v4: bug fixed in nu nubar H0 cross section (Fig.11), version to appear in PR

Top Radiative Corrections in Non-minimal Standard Models

We derive the one-loop effective action induced by a heavy top in models with an extended Higgs sector. We use the effective action to analyze the top corrections to the $\rho$ parameter and to the Higgs-gauge boson couplings. We show that in models with $\rho\not=1$ at tree-level, one does not lose generally the bound on $m_t$ from the $\rho$ parameter.Comment: 9 pages, phyzzx file, UPR-0603T. (a new reference has been added