Related papers: Probing vector-like top partner from same-sign dil…
The discovery of the Higgs boson suggests that also neutrinos get their mass from spontaneous symmetry breaking. In the simplest ungauged lepton number scheme, the Standard Model (SM) Higgs has now two other partners: a massive CP-even, as…
We investigate production and detection prospects of the quintuplet heavy leptons at the LHC in the context of a new model which is proposed as a viable and testable solution to the neutrino masses problem. We classify the signals, carry…
The elastic production of top quark pairs in $pp$ collisions at low and high luminosity regimes is investigated in detail. We extend the study performed in Phys. Rev. D102, 074014 (2020) which has demonstrated that the sum of two…
Relatively light Top Partners are unmistakable signatures of reasonably Natural Composite Higgs models and as such they are worth searching for at the LHC. Their phenomenology is characterized by a certain amount of model-dependence, which…
A search for a heavy neutral lepton N of Majorana nature decaying into a W boson and a charged lepton is performed using the CMS detector at the LHC. The targeted signature consists of three prompt charged leptons in any flavor combination…
We investigate the discovery prospects for a vector-like top partner (VLT) in the Type-II Two-Higgs-Doublet Model (2HDM-II) extended by a vector-like quark doublet ($TB$) at the 14~TeV LHC. The study focuses on the pair production process…
In compressed supersymmetry, a light top squark naturally mediates efficient neutralino pair annihilation to govern the thermal relic abundance of dark matter. I study the LHC signal of same-sign leptonic top-quark decays from gluino and…
We analyze the LHC prospects for measurements of the $t\bar{t}$ pair produced exclusively in photon-photon or semi-exclusively in photon-Pomeron and Pomeron-Pomeron processes using protons tagged in forward proton detectors on both sides of…
We update present bounds on the helicity of the neutrinos produced in muon decay, including e+ e- -> fbar f LEP 2 data. These significantly reduce the limits derived from all the other electroweak precision data. In Standard Model…
We discuss the possibility of observing multi-lepton signals at the Large Hadron Collider (LHC) from the production and decay of heavy Standard Model (SM) singlet neutrinos added in extensions of SM to explain the observed light neutrino…
Composite-fermion models predict excited quarks and leptons with mass scales which can potentially be observed at high-energy colliders like the LHC; the most recent exclusion limits from the CMS and ATLAS Collaborations corner…
A search for heavy right-handed Majorana neutrinos is performed with the ATLAS detector at the CERN Large Hadron Collider, using the 140 $\mathrm{fb}^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV collected during Run 2. This…
Leptoquark-Higgs interactions induce mixing between leptoquark states with different chiralities once the electro-weak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the…
If the neutrino is a Majorana particle, low-energy lepton-number-violating (LNV) processes, such as neutrinoless double-beta ($0\nu\beta\beta$) decay, are possible. It may also be possible to observe high-energy $0\nu\beta\beta$-like LNV…
In many models incorporating the type-I seesaw mechanism, the right-handed neutrino ($N$) couples to heavy vector/scalar bosons and thereby has resonant pair production. It barely receives attention thus far, however, it may provide the…
Although the top quark has been discovered in 1995 and studied extensively by the Tevatron experiments, the top quark will remain special for years to come due to unique opportunities it offers. Because of the large top-antitop production…
Naturalness demands that the quadratic divergence of the one-loop top contribution to the Higgs mass be cancelled at a scale below 1 TeV. This can be achieved by introducing a fermionic (spin-1/2) top partner, as in, for example, Little…
We consider how best to search for top partners in generic composite Higgs models. We begin by classifying the possible group representations carried by top partners in models with and without a custodial $SU(2)\times SU(2) \rtimes…
The search strategy or the finding of new effects for heavy neutrinos often relies on their different decay channels to detectable particles. In particular in this work we study the decay of a Majorana neutrino with interactions obtained…
Neutrinos in the Standard Model (SM) are considered to be massless which is in contradiction with the evidence from the neutrino oscillation data. These experiments established that at least two SM neutrinos have non-zero masses and that…