Related papers: Structure Formation with Majoron Supermultiplet
We analyse the effects of Dirac and Majorana neutrinos on leptonic decays of muon and tau leptons using the most general four-lepton effective interaction Hamiltonian of dimension six. We calculate the specific energy and angular…
We follow a minimalistic approach to neutrino masses, by introducing a single heavy singlet $N$ into the standard model (or supersymmetric standard model) with a heavy Majorana mass $M$, which couples as a single right-handed neutrino in a…
Knowledge of the mechanism of neutrino mass generation would help understand a lot more about Lepton Number Violation (LNV), the cosmological evolution of the Universe, or the evolu tion of astronomical objects. Here we propose a verifiable…
A supersymmetric model with four generations is proposed, in which the top quark is approximately degenerate in mass with the $W^{\pm}$ gauge boson, $m_t\simeq m_W$, leading to values of $R_b$ in better agreement with the present…
Recently a minimalistic scenario has been developed to explain dark matter and tiny but nonzero neutrino masses. In this scenario, a new scalar called SLIM plays the role of the dark matter. Neutrinos achieve Majorana mass through a…
Late-decaying string moduli dilute the baryon asymmetry of the universe created in any previous era. The reheat temperature for such moduli is below a GeV, thus motivating baryogenesis at very low temperatures. We present an extension of…
A `new' scenario is proposed for baryogenesis. We show that delayed decay of coloured Higgs particles in grand unified theories may generate excess baryon number of the empirically desired amount, if the mass of the heaviest neutrino is in…
We present a search for a neutral particle, pair-produced in p-pbar collisions at sqrt(s)=1.96 TeV, which decays into two muons and lives long enough to travel at least 5 cm before decaying. The analysis uses ~380 pb^-1 of data recorded…
We study sterile neutrino dark matter (DM) in a classically conformal U(1)' extension of the Standard Model with three right-handed neutrinos and a Majoron-like singlet scalar that generate the observed pattern of active neutrino masses and…
We propose a scenario of thermal leptogenesis at the TeV scale in the context of an extension of the Standard Model with 4 generations. We also add one right-handed Majorana neutrino for each generation to generate left handed neutrino…
In theories with a low quantum gravity scale, global symmetries are expected to be violated, inducing excessive proton decay or large Majorana neutrino masses. The simplest cure is to impose discrete gauge symmetries, which in turn make…
A search for the electroweak production of charginos, neutralinos and sleptons decaying into final states involving two or three electrons or muons is presented. The analysis is based on 36.1 fb$^{-1}$ of $\sqrt{s}=13$ TeV proton-proton…
The minimal flipped $SU(5)$ unification with the right-handed neutrino Majorana mass scale generated as a two-loop effect is arguably one of the most constrained models of perturbative baryon and lepton number violation currently on the…
Neutrinos, being massive, can decay. A heavier neutrino could decay into a lighter one and a massless scalar or pseudoscalar boson, such as the Majoron. Two-body non-radiative decay could occur in dense matter, such as in the inner dense…
A new mechanism for understanding small neutrino masses using only simple new physics at the TeV scale is proposed. As an application, it is shown how it can naturally lead to the mass hierarchy of the so called bimaximal mixing in the case…
We extend the Type I and Type III seesaw mechanisms to generate neutrino masses within the left-right symmetric theories where parity is spontaneously broken. We construct a next to minimal left-right symmetric model where neutrino masses…
Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions…
A search for heavy Majorana neutrinos produced in the $B^- \to \pi^+\mu^-\mu^-$ decay mode is performed using 3 fb$^{-1}$ of integrated luminosity collected with the LHCb detector in $pp$ collisions at center-of-mass energies of 7 TeV and 8…
We present a minimal extension of the standard model that includes a long-lived fermion with weak-scale mass and an ${\cal O}({\rm GeV})$ fermionic dark matter candidate both of which are coupled to quarks. Decays of a TeV-scale colored…
We demonstrate here that the mini-split version of the Minimal Supersymmetric Standard Model (MSSM) including R-parity violating couplings naturally provides all the necessary ingredients for a novel baryogenesis mechanism. The baryogenesis…