Related papers: Sterile neutrinos in lepton number and lepton flav…
A sterile neutrino at GeV mass scale is of particular interest in this work. Though not take part in neutrino oscillation, the sterile neutrino can induce flavor violating semileptonic and leptonic decay of $K, D$ and $B$ mesons. We…
Matrix element $U_{\tau N}$ of sterile neutrino N mixing with $\nu_{\tau}$ is the least constrained in the literature among the three $U_{\alpha N}$ ($\alpha=e,\mu,\tau$) mixing parameters characterizing the sterile neutrino phenomenology.…
The phenomenon of neutrino flavor oscillations motivates searches for sterile neutrinos in a broad range of masses and mixing-parameter values. A sterile neutrino $N$ that mixes predominantly with the $\tau$ neutrino is particularly…
In modern experiments on flavour physics it is possible to search for the decays of $B$ or $D$ mesons or $\tau$ leptons into final states with heavy neutrinos $N$ (a.k.a. heavy neutral leptons). I present a common study of theorists and…
In this work, we study the lepton-number-violating processes of $K^\pm$ and $D^\pm$ mesons. Two quasi-degenerate sterile neutrinos are assumed to induce such processes. Different with the case where only one sterile neutrino involves, here,…
In this article we investigate the prospects of searching for sterile neutrinos in lowscale seesaw scenarios via the lepton flavour violating (but lepton number conserving) dilepton dijet signature. In our study, we focus on the final state…
In a scenario with two almost mass degenerate heavy sterile Majorana neutrinos with a mass $\sim 1$ GeV, we present the semileptonic decay widths of heavy charged pseudoscalars such as $B$ mesons, either lepton-number-violating ($B^{\pm}…
We present an overview of recent progress in the phenomenological study of neutrino masses, lepton flavor mixing and CP violation. We concentrate on the model-independent properties of massive neutrinos, both in vacuum and in matter.…
We address the impact of a modified $W \ell \nu$ coupling on a wide range of observables, such as $\tau$ leptonic and mesonic decays, leptonic decays of pseudoscalar mesons, as well as semileptonic meson decays. In particular, we…
We make a comparative study of the neutrinoless double beta decay constraints on heavy sterile neutrinos versus other direct and indirect constraints from both lepton number conserving and violating processes, as a sensitive probe of the…
We study lepton number violating decays of charged K, D, D_s, B and B_c mesons of the form M^+\to {M'}^-\ell^+\ell^+, induced by the existence of Majorana neutrinos. These processes provide information complementary to neutrinoless double…
An observation of any lepton number violating process will undoubtedly point towards the existence of new physics and indirectly to the clear Majorana nature of the exchanged fermion. In this work, we explore the potential of a minimal…
We study possible contributions of heavy sterile neutrinos $\nu_h$ to the decays $\tau^-\to e^{\pm}(\mu^{\pm})\pi^{\mp}\pi^-$. From the experimental upper bounds on their rates we derive new constraints on the $\nu_h-\nu_{\tau}$ mixing in…
The motivation for the search for $0\nu\beta\beta$ decay is briefly reviewed. It is stressed that the exchange of light Majorana neutrinos is not the only possible mechanism of the decay. The link between lepton number and lepton flavor…
We examine medium-enhanced, neutrino scattering-induced decoherent production of dark matter candidate sterile neutrinos in the early universe. In cases with a significant net lepton number we find two resonances, where the effective…
Using a three neutrino framework we investigate bounds for the effective Majorana neutrino mass matrix. The mass measured in neutrinoless double beta decay is its (11) element. Lepton-number and -flavor violating processes sensitive to each…
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…
We assume that the mass matrix of active neutrinos has hierarchical form with small mixings, similar to quark mass matrix. We show that the large mixings between $\nu_\mu$ and $\nu_\tau$ as well as between $\nu_e$ and certain combination of…
We delineate the maximal parameter space of sterile neutrino dark matter in the presence of lepton flavor asymmetries. We focus on large flavor asymmetries with vanishing total lepton asymmetry, which are washed out by neutrino oscillations…
Sterile neutrinos with masses $\sim 0.1$ eV or higher would play an important role in astrophysics and cosmology. We explore possible signatures of such sterile neutrinos at long baseline experiments. We determine the neutrino conversion…