Abstract
Neutrino physics is a mature branch of science with all the three neutrino mixing angles and two mass squared differences determined with high precision. In spite of several experimental verifications of neutrino oscillations and precise measurements of two mass squared differences and the three mixing angles, the unitarity of the leptonic mixing matrix is not yet established, leaving room for the presence of small nonunitarity effects. Deriving the bounds on these nonunitarity parameters from existing experimental constraints, on cLFV decays such as μ→eγ, μ→τγ, and τ→eγ, we study their effects on the generation of baryon asymmetry through leptogenesis and neutrino oscillation probabilities. We consider a model where see-saw is extended by an additional singlet S which is very light but can give rise to nonunitarity effects without affecting the form on see-saw formula. We do a parameter scan of a minimal see-saw model in a type I see-saw framework satisfying the Planck data on baryon to photon ratio of the Universe, which lies in the interval 5.8×10-10<YB<6.6×10-10(BBN). We predict values of lightest neutrino mass and Dirac and Majorana CP-violating phases δCP, α, and β, for normal hierarchy and inverted hierarchy for one-flavor leptogenesis. It is worth mentioning that all these four quantities are unknown yet, and future experiments will be measuring them.
Highlights
IntroductionThere are 3 known flavors of neutrinos, ]푒, ]휇, and ]휏, each of which couples only to the charged lepton of the same flavor
We find that M1 = 1012 GeV is favored in the light of baryon asymmetry of the Universe for one-flavor regime
In this work, we have considered the possibility that the neutrino mixing matrix, U푃푀푁푆, could be nonunitary and calculated the limits on nonunitary parameters η휇푒, η휏푒, and η휏휇 from latest constraints on branching ratios of cLFV decays
Summary
There are 3 known flavors of neutrinos, ]푒, ]휇, and ]휏, each of which couples only to the charged lepton of the same flavor. The discoveries of neutrino mass and leptonic mixing have come from the observation of neutrino flavor change, ]훼 → ]훽. CP violation interchanges every particle in a process by its antiparticle. This CP violation can be produced by the phase δ퐶푃 in U. Neutrinos can have two types of mass term in the Lagrangian−Dirac and Majorana mass terms. To determine whether Majorana masses occur in nature, so that ]푖 = ]푖, the favorable approach to seek is Neutrinoless Double Beta Decay (0]ββ)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
