Related papers: Muon conversion to electron in nuclei in type-I se…
The exotic neutrinoless $\mu^- - e^-$ nuclear conversion is studied within the conventional extensions of the standard model as well as in the minimal supersymmetric (SUSY) models with and without R-parity conservation. The dependence of…
The CMS $e^+ e^- jj$ events of invariant mass near 2 TeV are consistent with a $W'$ boson decaying into an electron and a right-handed neutrino whose TeV-scale mass is of the Dirac type. We show that the Dirac partner of the right-handed…
Using a 3 + 1 neutrino model with one sterile and the three standard active neutrinos with a 4x4 unitary transformation matrix, U, relating flavor to mass neutrino states, the probability of $\nu_\mu$ to $\nu_e$ transition is estimated…
A joint effort of cryogenic microcalorimetry (CM) and high-precision Penning-trap mass spectrometry (PT-MS) in investigating atomic orbital electron capture (EC) can shed light on the possible existence of heavy sterile neutrinos with…
We study in this research the phenomenology of $\mu\to e\gamma$ decay in a scenario of the class of extended models with non-sterile right-handed (RH) neutrino at electroweak (EW) scale proposed by P.Q. Hung. Field content of the standard…
The type-I seesaw Lagrangian yields a non-generic set of active-sterile oscillation parameters - the neutrino mass eigenvalues and the physical elements of the full mixing matrix are entwined. For this reason one is able to, in principle,…
Motivated by recent results from neutrino experiments, we study the neutrino masses and mixing in the framework of a SUSY $SU(5)\times \mathbb{A}_{4} $ model. The hybrid of Type I and Type II seesaw mechanisms leads to the nonzero value of…
We construct a model in which the neutrino Dirac mass terms are of order the electron mass and the seesaw mechanism proceeds via right-handed neutrinos with masses of order TeV. In our model the spectra of the three light and of the three…
Some of basic problems in neutrino physics such as new energy scales, the enormous gap between neutrino masses and the lightest charged fermion mass, possible existance of sterile neutrinos in eV mass range are studied in the local gauge…
The calculation of the $\mu$ decay is performed in V-A theory taking into account that, in agreement with the observation of the oscillations, the neutrinos must be massive. Provided that the masses of the electron and muon neutrinos are…
We summarize recent work to develop an effective theory of muon-to-electron conversion, based on a complete set of low-energy effective operators that are developed from a systematic expansion in velocities and momenta. The expansion…
The measured values for the mixture angles in neutrino oscillations suggest the existence of a symmetry of interchange of flavor between muon and tau neutrinos. Using this symmetry we analyzed the minimal seesaw model for neutrino masses,…
Motivated by the recent investigation of neutrinoless $\tau$-lepton decays by the CLEO collaboration, we perform a systematic analysis of such decays in a possible new-physics scenario with heavy Dirac/Majorana neutrinos, including…
It is shown that the singular seesaw mechanism can simultaneously explain all the existing data supporting nonzero neutrino masses and mixing. The three mass-squared differences that are needed to accommodate the atmospheric neutrino data…
Contrary to the common lore based on naive dimensional analysis, the seesaw scale for neutrino masses can be naturally in the TeV range, with small parameters coming from radiative corrections. We present one such class of type-I seesaw…
We investigate TeV scale seesaw scenarios at $\mu^+ e^-$ and $\mu^+ \mu^+$ colliders in the $\mu$TRISTAN experiment. In minimal type-I seesaw scenario we consider two generations of Standard Model (SM) singlet heavy Majorana type Right…
Recently a new method for determining the neutrino mass hierarchy by comparing the effective values of the atmospheric \Delta m^2 measured in the electron neutrino disappearance channel, \Delta m^2(ee), with the one measured in the muon…
We present predictions for $\mu \to e \gamma$ and $\tau \to \mu \gamma$ in the CMSSM in which there is a natural hierarchy of neutrino masses resulting from the sequential dominance of three right-handed neutrinos. We perform a global…
We examine a phenomenon recently predicted by numerical simulations of supernova neutrino flavor evolution: the swapping of supernova $\nu_e$ and $\nu_{\mu,\tau}$ energy spectra below (above) energy $\EC$ for the normal (inverted) neutrino…
Nuclear matrix elements (NME) for exchange of arbitrary mass neutrinos are calculated in the interacting boson model (IBM-2). By combining the NME with the phase space factors (PSF), expected half-lives for neutrinos of mass $m_N$ and…