Related papers: Flavor changing neutral couplings for leptons
We provide a general classification of flavour symmetries according to their interplay with the proper Poincare' and gauge groups and to their linear or nonlinear action in field space. We focus on the lepton sector and we review the…
High energy cosmic neutrino fluxes can be produced inside relativistic jets under the envelopes of collapsing stars. In the energy range E ~ (0.3 - 1e5) GeV, flavor conversion of these neutrinos is modified by various matter effects inside…
In a recent paper, we pointed out that mixing of the light neutrinos with heavy gauge singlet states could reconcile the Z-pole data from e+e- colliders and the nu_mu (anti-nu_mu) scattering data from the NuTeV experiment at Fermilab. We…
$SU(2)_L$-invariance links charged dilepton and dineutrino couplings. Phenomenological implications are worked out for flavor changing neutral currents involving strange, charm, beauty and top quark transitions in a model-independent way.…
Neutrino-neutrino refraction dominates the flavor evolution in core-collapse supernovae, neutron-star mergers, and the early universe. Ordinary neutrino flavor conversion develops on timescales determined by the vacuum oscillation…
We consider a class of models predicting new heavy neutral fermionic states, whose mixing with the light neutrinos can be naturally significant and produce observable effects below the threshold for their production. We update the indirect…
If there are scalar particles of small or moderate mass coupled very weakly to Dirac neutrinos, in a minimal way, then neutrino-anti-neutrino clouds of sufficient number density can experience an instability in which helicities are suddenly…
In this short review we discuss the notion of lepton numbers. The strong evidence in favor of neutrino oscillations obtained recently in the Super-Kamiokande atmospheric neutrino experiment and in solar neutrino experiments imply that the…
Approximate flavor symmetries in the quark sector have been used as a handle on physics beyond the Standard Model. Due to the great interest in neutrino masses and mixings and the wealth of existing and proposed neutrino experiments it is…
Neutrinos in a core-collapse supernova undergo coherent flavor transformations in their own background. We explore this phenomenon during the cooling stage of the explosion. Our three-flavor calculations reveal qualitatively new effects…
We define a new class of $Z'$ models with neutral flavor-changing interactions at tree level in the down-quark sector. They are related in an exact way to elements of the quark mixing matrix due to an underlying flavored $U(1)'$ gauge…
We construct a flavour guided model that realises the distinctive Echo 12-23 Texture in the neutrino mass matrix through a non-trivial interplay of symmetries. While the model accounts for charged lepton mass hierarchy, the texture offers…
A mechanism has been suggested recently to generate the neutrino mass out of a dimension-seven operator. This is expected to relieve the tension between the occurrence of a tiny neutrino mass and the observability of other physics effects…
The definition of `lepton flavour eigenstates' introduced in a recent paper hep-ph/0302045 is in disagreement with the Standard Model prediction for the structure of the leptonic charged current and implies the absence of neutrino…
The U(1) flavor symmetry explains the large mixing of neutrinos while it leads to the unique texture for the quark mass matrices. It is remarked that U(1) symmetric mass matrices have the phenomenological defects. In the quark sector, the…
Behind the observed pattern of lepton flavor mixing is a partial or approximate mu-tau flavor symmetry --- a milestone on our road to the true origin of neutrino masses and flavor structures. In this review article we first describe the…
Flavour physics represents one of the most interesting and, at the same time, less understood sector of the Standard Theory. On the one hand, the peculiar pattern of quark and lepton masses, and their mixing angles, may be the clue to some…
New heavy neutral leptons lead to non-unitary effects in models for neutrino masses. Such effects could represent a sign of new physics beyond the Standard Model, leading to observable deviations in neutrino oscillation experiments, lepton…
We argue that neutrino flavor parameters may exhibit features that are very different from those of quarks and charged leptons. Specifically, within the Froggatt-Nielsen (FN) framework, charged fermion parameters depend on the ratio between…
In this brief review, I discuss the new physics unveiled by neutrino oscillation experiments over the past several years, and discuss several attempts at understanding the mechanism behind neutrino masses and lepton mixing. It is fair to…