Related papers: Characterizing Heavy Neutral Fermions via their De…
We consider the possibility of Majorana neutrinos production at the Large Hadron Collider (LHC) by studying the $pp \rightarrow l_i^{+} l_j^{+} +2~jets$ ($l_j\equiv e ,\mu$) process which, due to leptonic number violation, is a clear…
A search for neutral heavy leptons (NHLs) has been performed using an instrumented decay channel at the NuTeV (E-815) experiment at Fermilab. The decay channel was composed of helium bags interspersed with drift chambers, and was used in…
Recent experimental results suggest that the neutrinos of the Standard Model are massive, though light. Therefore they may mix with each other giving rise to lepton flavour or even lepton number violating processes, depending on whether…
The minimally extended standard model of particle physics contains three right handed or sterile neutrinos, coupled to the active ones by a Dirac mass matrix and mutually by a Majorana mass matrix. In the pseudo-Dirac case, the Majorana…
Heavy neutral leptons (HNLs) are hypothetical particles proposed as a potential explanation for neutrino oscillations and the generation of the baryon asymmetry in the Universe. This paper focuses on HNLs with masses significantly above the…
We study the dominant signatures that arise in Higgs physics at colliders when extending the Standard Model (SM) with a Yukawa interaction to heavy neutral leptons (HNL), while suppressing their mixing to active neutrinos. We focus on the…
A search for heavy neutral leptons (HNLs) decaying in the CMS muon system is presented. A data sample is used corresponding to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}$ = 13 TeV, recorded at the…
An extension of the Standard Model by three singlet fermions with masses smaller than the electroweak scale allows to explain simultaneously neutrino oscillations, dark matter and baryon asymmetry of the Universe. We discuss the properties…
Neutrinoless hadron Lepton Number Violating (LNV) decays can be induced by virtual Majorana neutrino, which in turn indubitably show the Majorana nature of neutrinos. Many three-body LNV processes and Lepton Flavour Violating (LFV)…
Two general models with hierarchical and almost degenerate neutrino masses, which are able to explain the solar and atmospheric anomalies are investigated. We show how neutrinoless double beta decay experiments discern Dirac and Majorana…
We study the phenomenology of heavy neutral leptons (HNLs) at the LHC in effective field theory, concentrating on $d=6$ operators with top quarks. Depending on the operator choice and HNL mass, the HNLs will be produced either from…
We consider the non-radiative two body decay of a neutrino to a daughter neutrino with degraded energy and a very light particle (Majoron). Ultrahigh energy neutrinos from an astrophysical source like a Gamma Ray Burst undergoing this decay…
Stopped muons, which are generic in pion-at-rest experiments, can shed light on heavy neutral leptons (HNLs) in unexplored parameter spaces. If the HNL is lighter than the muon, the HNL can be produced from decays of muons and pions.The HNL…
A search for long-lived heavy neutral leptons (HNLs) using proton-proton collision data corresponding to an integrated luminosity of 138 fb$^{-1}$ collected at $\sqrt{s}$ = 13 TeV with the CMS detector at the CERN LHC is presented. Events…
The model of heavy neutral leptons (HNLs) is one of the well-motivated models beyond the standard model (BSM) from both theoretical and phenomenological point of views. It is an indispensable ingredient to explain the puzzle of tiny…
We study lepton number violating and lepton number conserving semi-leptonic decays of heavy baryons $\Lambda_b^0$ to three charged leptons and a neutrino. The decays occur through two intermediate quasi-degenerate GeV-scale sterile…
Some of the outstanding questions of particle physics today concern the neutrino sector, in particular whether there are more neutrinos than those already known and whether they are Dirac or Majorana particles.There are different ways to…
Finding out if neutrinos are Dirac or Majorana particles is known to be extremely difficult. This is generally believed to be due to the smallness of the neutrino mass compared to typical neutrino energies, and to the fact that in the limit…
Neutrinos can be pseudo-Dirac in Nature - they can be Majorana fermions while behaving effectively as Dirac fermions. Such scenarios predict active-sterile neutrino oscillations driven by a tiny mass-squared difference $(\delta m^2)$, which…
We investigate the LHC discovery potential for electroweak scale heavy neutrino singlets (seesaw I), scalar triplets (seesaw II) and fermion triplets (seesaw III). For seesaw I we consider a heavy Majorana neutrino coupling to the electron…