Related papers: Probing extra dimensions through the invisible Hig…
This thesis presents a theoretical analysis of the properties of the Higgs bosons in the Standard Model (SM) and the minimal supersymmetric extension (MSSM), which can be investigated at the LHC and $e^+e^-$ linear colliders. The final goal…
Searching for new Higgs particle beyond the observed light Higgs boson h(125GeV) will unambiguously point to new physics beyond the standard model. We study the resonant production of a CP-even heavy Higgs state $H^0$ in the di-Higgs…
The ATLAS and CMS experiments have an ambitious search program for charged Higgs bosons. The two main searches for $H^\pm$ at the LHC have traditionally been performed in the $\tau \nu$ and $t b$ decay channels, as they provide the…
The Standard Model (SM) predicts a branching ratio of the Higgs boson decaying to invisible particles of $\mathcal{O}$(0.001), though current measurements have only set upper limits on this value. The small SM-allowed rate can be enhanced…
Recent LEP searches for Higgs bosons in models other than the Minimal Standard Model and the Minimal Supersymetric Standard Model are reviewed. Limits are presented for Higgs bosons decaying into diphotons or invisible particles, and for…
A search is conducted for a new beyond-the-Standard-Model boson using events where a Higgs boson with mass 125 GeV decays to four leptons ($\ell =$ $e$ or $\mu$). This decay is presumed to occur via an intermediate state which contains one…
We have investigated charged Higgs boson production via the gluon-bottom quark mode, gb -> tH+, followed by its decay into a chargino and a neutralino. The calculations are based on masses and couplings given by the Minimal Supersymmetric…
The ATLAS and CMS experiments have recently claimed discovery of a Higgs boson-like particle at ~5 sigma confidence and are beginning to test the Standard Model predictions for its production and decay. In a variety of supersymmetric…
We have investigated the signal for physics beyond the Standard Model via Higgs plus photon final state, hitherto unobserved at the LHC, in the framework of Standard Model Effective Field Theory. Using the relevant dimension-6 operators, we…
One of the cleanest signatures of a heavy Higgs boson in models with vectorlike leptons is $H\to e_4^\pm \ell^\mp \to h\ell^+\ell^-$ which, in two Higgs doublet model type-II, can even be the dominant decay mode of heavy Higgses. Among the…
We investigate the phenomenology of the charged Higgs boson at the International Linear Collider (ILC) within the framework of the type-X Two-Higgs Doublet Model (2HDM), where a light charged Higgs boson, with a mass around 200 GeV or even…
Most models of new physics contain extended Higgs sectors with multiple Higgs bosons. The observation of an additional Higgs boson, besides the $\sim 125$ GeV `$h_{\rm obs}$', will thus serve as an irrefutable evidence of physics beyond the…
The observability of charged Higgs $ H^{\pm} $ has been investigated at future lepton collider by assuming type-I 2HDM, at a centre of mass energy $ \sqrt{s}=1.5$ TeV. The signal process chain is $ e^{+}e^{-} \rightarrow Z^{*}/…
Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected…
If supersymmetry is broken independently in multiple sectors with different scales, a number of goldstinos will be generated. One linear combination of these goldstinos is massless and eaten by the gravitino, while the orthogonal…
Although the existence of Dark Matter (DM) has been suggested by various astrophysical observations, it has not yet been discovered today. We can assume a scenario in which the particles that account for the DM can interact with the…
We consider a simple extension of the standard model with a singlet fermionic dark matter. Its thermal relic density can be easily accommodated by a real singlet scalar messenger that mixes with the standard model Higgs boson. The model can…
The Higgs boson was the last fundamental piece of the Standard Model to be experimentally confirmed. LHC is embarked in a quest to probe the possibility that this particle provides a portal to new physics. One front of this quest consists…
The CMS and ATLAS experiments at the LHC have announced the discovery of a Higgs boson with mass at approximately 125 $GeV/c^{2}$ in the search for the Standard Model Higgs boson via notably the $\gamma\gamma$ and $ZZ$ to four leptons final…
A search for evidence of invisible-particle decay modes of a Higgs boson produced in association with a Z boson at the Large Hadron Collider is presented. No deviation from the Standard Model expectation is observed in 4.5 fb$^{-1}$ (20.3…