Related papers: Muon conversion to electron in nuclei in type-I se…
Assuming Majorana neutrinos, we infer from oscillation data the expected values of the parameters m_{nu_e} and m_{ee} probed by beta and 0nu2beta-decay experiments. If neutrinos have a `normal hierarchy' we get the 90% CL ranges |m_{ee}| =…
Improved upper bounds are presented on the coupling $|U_{e4}|^2$ of an electron to a sterile neutrino $\nu_4$ from analyses of data on nuclear and particle decays, including superallowed nuclear beta decays, the ratios…
We explore the low scale implications of the Pati-Salam Model including the TeV scale right-handed neutrinos interacting and mixing with the MSSM fields through the inverse seesaw (IS) mechanism in the light of the muon anomalous magnetic…
In this paper, we study the phenomenology of right-handed neutrino isosinglets. We consider the general situation where the neutrino masses are not necessarily given by $m_D^2/M$, where $m_D$ and $M$ are the Dirac and Majorana mass terms…
A sensitivity study of the search for heavy sterile neutrinos ($\nu_H$) in the MeV mass range using solar neutrino experiments is presented. $\nu_H$, with masses ranging from a few MeV up to around 15 MeV, can be produced in the Sun through…
The minimal interpretation of the atmospheric neutrino data suggests that the muon neutrino oscillates into another species with a mixing angle close to the maximal $\pi/4$. In the Exact Parity Symmetric Model, both the muon and electron…
We discuss a neutrino mass model based on the S_4 flavor symmetry within the minimal seesaw framework, in which only two right-handed neutrinos are introduced and transform as 2 under S_4. Although the model contains less free parameters…
The Superkamiokande experiment suggests the large flavor mixing between nu_mu and nu_tau. We show that the mixing angle receives significant corrections from the renormalization group equation (RGE) when both the second and the third…
The Mu2e experiment will search for a Standard Model violating rate of neutrinoless conversion of a muon into an electron in the presence of an aluminum nucleus. Observation of this charged lepton flavor violating process would be an…
New mu-to-e conversion searches aim to advance limits on charged lepton flavor violation (CLFV) by four orders of magnitude. By considering P and CP selection rules and the structure of possible charge and current densities, we show that…
In contrast to the original type I seesaw mechanism that requires right-handed Majorana neutrinos at energies much higher than the electroweak scale, the so-called low scale seesaw models allow lighter masses for the additional neutrinos.…
A natural extension of the standard model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6 \times6 neutrino mass matrix. We show that three light Majorana neutrinos…
Detailed dependence of resonant spin-flavor (RSF) conversion of supernova neutrinos on electron mole fraction Ye is investigated. Supernova explosion forms a hot-bubble and neutrino-driven wind region of which electron mole fraction exceeds…
Muonium is a bound state composed of an antimuon and an electron, and it constitutes a hydrogen-like atom. Because of the absence of the hadronic matter in the bound state, the muonium is a useful probe to explore new physics being free…
The combined requirements, of (i) a natural solution to the fermion mass hierarchy problem and (ii) an explanation of both the atmospheric and solar neutrino problems, lead to an essentially unique picture of neutrino masses and mixing…
We investigate mixing of neutrinos in the $\nu$MSM (neutrino Minimal Standard Model), which is the MSM extended by three right-handed neutrinos. Especially, we study elements of the mixing matrix $\Theta_{\alpha I}$ between three…
Searches for charged lepton flavor violation (CLFV) offer deep probes for a range of new physics scenarios, such as super-symmetric models, theories involving scalar leptoquarks or additional Higgs doublets, and models explaining the…
We consider seesaw type-I models including at least one (mostly-)sterile neutrino with mass at the eV scale. Three distinct situations are found, where the presence of light extra neutrinos is naturally justified by an approximately…
The Mu2e experiment at Fermilab is being designed to study the coherent neutrino-less conversion of a negative muon into an electron in the field of a nucleus. This process has an extremely low probability in the Standard Model, and its…
The simplest explanation for the atmospheric neutrino anomaly is the transition of muon neutrinos and antineutrinos into states of different flavor. Data from the reactor experiment Chooz, and the measurement of the energy and angle…