Related papers: Electroweak scale seesaw and heavy Dirac neutrino …
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…
We review the present electroweak precision data constraints on the mediators of the three types of see-saw mechanisms. Except in the see-saw mechanism of type I, with the heavy neutrino singlets being mainly produced through their mixing…
The comparison of samples with different number of charged leptons shows that trilepton signals are the most significant ones for seesaw mediators. As previously pointed out, this is indeed the case for scalar (type II) and fermion (type…
Neutrino masses can be generated by fermion triplets with TeV-scale mass, that would manifest at LHC as production of two leptons together with two heavy SM vectors or higgs, giving rise to final states such as 2 leptons + 4 jets (that can…
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…
We study LHC signatures of Type III seesaw in which SU(2)_L triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model…
In the type-I seesaw model the size of mixing between light and heavy neutrinos, nu and N, respectively, is of order the square root of their mass ratio, (m_nu/m_N)^(1/2), with only one generation of the neutrinos. Since the light-neutrino…
We study the collider signature of pseudo-Dirac heavy neutrinos in the inverse seesaw scenario, where the heavy neutrinos with mass at the electroweak scale can have sizable mixings with the Standard Model neutrinos, while providing the…
Seesaw models with a small lepton number breaking can naturally accommodate electroweak-scale pseudo-Dirac neutrinos with a sizable mixing with the active neutrinos, while satisfying the light neutrino oscillation data. Due to the smallness…
The Majorana neutrino in type-I seesaw and the pseudo-Dirac neutrinos in the inverse seesaw can have sizable mixings with the light neutrinos in the standard model (SM), through which the heavy neutrinos can be produced at the Large Hadron…
We study the implementation of the type III seesaw in the ordinary nonsupersymmetric SU(5) grand unified theory. This allows for an alternative definition of the minimal SU(5) model, with the inclusion of the adjoint fermionic multiplet.…
We propose a $B-L$ gauged extension of the Standard Model where light neutrino masses arise from type III seesaw mechanism. Unlike the minimal $B-L$ model with three right handed neutrinos having unit lepton number each, the model with…
A search is presented in proton-proton collisions at sqrt(s) = 7 TeV for fermionic triplet states expected in type III seesaw models. The search is performed using final states with three isolated charged leptons and an imbalance in…
We consider the low scale ($10$ - $100$ TeV) left-right symmetric model with "naturally" small neutrino masses generated through the inverse seesaw mechanism. The Dirac neutrino mass terms are taken to be similar to the masses of charged…
We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family…
We propose TeV-scale Dirac fermions producing Majorana masses of the known neutrinos via tree-level seesaw, different from standard type I and III seesaw. The employed weak five-plet with nonzero hypercharge leads to new seesaw formula…
A novel scenario is presented within the Type-I seesaw mechanism in which no other beyond Standard Model fields except three heavy right handed neutrinos, have been considered. Light neutrino masses around sub eV scale, could be possible at…
We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation…
A simple extension of the Standard Model providing TeV scale seesaw mechanism is presented. Beside the Standard Model particles and right-handed Majorana neutrinos, the model contains a singly charged scalar, an extra Higgs doublet and…
The lightness of the Standard Model (SM) neutrinos could be understood if their masses were to be generated by new physics at a high scale, through the so-called seesaw mechanism involving heavy fermion singlets. If new physics violates…