Related papers: A clean signal for a top-like isosinglet fermion a…
A natural, non-supersymmetric solution to the hierarchy problem generically requires fermionic partners of the top quark with masses not much heavier than 500 GeV. We study the pair production and detection at the LHC of the top partners…
The charged Higgs bosons can be produced as a resonance in s-channel single top events. The light charged Higgs in such events preferably decays to a pair of $\tau \nu$ thus making it difficult to distinguish from the large single W events…
This study provides a comprehensive phenomenological investigation into the discovery potential of heavy Higgs boson pairs ($HH, HA, AA, H^+H^-$) at a $\sqrt{s}=6$~TeV Muon Collider. Utilizing the Two-Higgs-Doublet Model (2HDM) Type-I…
A search for heavy pseudoscalar ($A$) and scalar ($H$) Higgs bosons decaying into a top quark pair ($t\bar{t}$) has been performed with 20.3 fb$^{-1}$ of proton--proton collision data collected by the ATLAS experiment at the Large Hadron…
We study the signals for a "fermiophobic" charged Higgs boson present in an extension of the standard model with an additional Higgs doublet and right handed neutrinos, responsible for generating Dirac-type neutrino masses. We study the…
Many new-physics models, especially those with a color-triplet top-quark partner, contain a heavy color-octet state. The "naturalness" argument for a light Higgs boson requires that the color-octet state be not much heavier than a TeV, and…
We discuss the viability of $gb \to tH \to ttb$ charged-Higgs signals at the proposed LHC $pp$ supercollider, in the decay channel $tt \to (bq \bar q')(b \ell \nu)$. Here one top quark decays hadronically and one semileptonically, with all…
A search for a high mass standard-model-like Higgs boson decaying into two Z bosons with subsequent decay into two leptons and two quarks performed at CMS is presented. The analysis is based on 19.7 1/fb of proton-proton collisions produced…
The production of the Higgs boson in association with a single top quark is sensitive to the relative sign of the coupling parameters describing its interaction with fermions and gauge bosons. The tHq production mode therefore provides an…
A search is presented for massive spin-1 Z' resonances decaying to a top quark and a heavy vector-like top quark partner T. The search is based on a 2.6 inverse femtobarns sample of proton-proton collisions at 13 TeV collected with the CMS…
We evaluate the discovery potential for the heavy Higgs bosons at the LHC energy upgrade with $\sqrt{s}=27$ TeV. We take degenerate mass spectrum and assume near the alignment limit in the Type-II Two Higgs Doublet Model for illustration.…
Several extensions of the Standard Model have light doubly-charged Higgs bosons in their particle spectrum. The supersymmetric versions of these models introduce fermionic superpartners of these doubly-charged Higgs bosons, the Higgsinos,…
A search is presented for the pair production of heavy vector-like quarks, $T\bar T$ or $B\bar B$, that decay into final states with jets and no reconstructed leptons. Jets in the final state are classified using a deep neural network as…
Current Higgs data show an ambiguity in the value of the Yukawa couplings to quarks and leptons. Not so much because of still large uncertainties in the measurements but as the result of several almost degenerate minima in the coupling…
We investigate the discovery prospects for a vector-like top partner ($T$) within the Type-II Two-Higgs-Doublet Model (2HDM-II) at future high-energy $\mu p$ colliders. The analysis focuses on the charged Higgs decay mode $\mu^+ p \to…
A scenario is presented where the $s$, $c$, and $b$ quark fusion Higgs production cross sections are enhanced with respect to those of the Standard Model. In particular the $c$ quark fusion production is very important and can account for a…
Vectorlike fermions are an important target for hadron collider searches. We show that the vectorlike quarks may predominantly decay via higher-dimensional operators into a quark plus a couple of other Standard Model fermions. Pair…
Within the framework of the type-II Two Higgs Doublet Model (2HDM-II) we study the production of three top quarks at the Large Hadron Collider (LHC). In the Standard Model the production cross section of three tops is low ($\approx 3$fb),…
Based on a simplified model including a singlet vector-like top quark $T$ with charge $|Q|=2/3$, we analyze the prospects of observing $T$ via the single $T$ production in the $tZ$ channel with $Z$ decaying to neutrinos at the hadron-hadron…
A search for pair-produced heavy vector-like charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T…