Related papers: Are Neutrinos Democratic?
Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing…
Data on solar and atmospheric neutrinos provide evidence for neutrino masses and mixings. We review some basic neutrino properties, the status of neutrino oscillations and implications for grand unified theories, including leptogenesis.
Recent atmospheric and solar neutrino experiments suggest that neutrinos have small but nonzero masses. They further suggest that mass eigenvalues have certain degree of hierarchical structures, and also some mixing angles are near-maximal…
We propose an effective mass matrix for light neutrinos which is consistent with the mixing pattern indicated by solar and atmospheric neutrino experiments. Two scenarios for the mass eigenvalues are discussed and the connection with double…
In this review we present the main features of the current status of neutrino physics. After a review of the theory of neutrino mixing and oscillations, we discuss the current status of solar and atmospheric neutrino oscillation…
Neutrino masses and mixings are investigated on the basis of a universal seesaw mass matrix model, in which quark (except for top) and charged lepton mass matrices M_f and neutrino mass matrix M_\nu are given by M_f \simeq m_L M_F^{-1} m_R…
Nonzero neutrino masses are the first definitive need to extend the standard model. After reviewing the basic framework, I describe the status of some of the major issues, including tests of the basic framework of neutrino masses and…
Astrophysical implications of neutrino mass and mixings are discussed. The status of solar and atmospheric neutrino problems, and recent developments concerning nuclear physics input to solar models and solar opacities are reviewed.…
The Standard Model has been incredibly successful in predicting the outcome of almost all the experiments done up so far. In it, neutrinos are mass-less. However, in recent years we have accumulated evidence pointing to tiny masses for the…
Neutrino masses and mixing are generated in a supersymmetric standard model when R-parity is violated in bilinear mass terms. The mixing matrix among the neutrinos takes a restrictive form if the lepton flavor universality holds in the…
We argue that the accumulated neutrino data, including recent results from KamLAND and K2K, point to a neutrino mixing matrix with (V_{11}, V_{21}, V_{31}; V_{21}, V_{22}, V_{32}; V_{13}, V_{23}, V_{33}) = (-2/\sqrt{6}, 1/\sqrt{6},…
We investigate a model with an extra $Z_{2}$ gauge symmetry in the Standard Model. We assume that only the scalars and the leptons carry non-zero charge. The symmetry gives a structure to the mass matrix for the neutrinos. With two extra…
Observations of atmospheric neutrinos offer compelling evidence that neutrinos have mass and do oscillate. Preliminary data are compatible with maximal $\nu_\mu$--$\nu_\tau$ mixing, but not with pure $\nu_\mu$--$\nu_e$ mixing. In a general…
If neutrinos have mass, we give reasons for a possible pattern of three (squared) mass eigenvalues: $m_1^2 \simeq (2.8 - 5.8) \, \mbox{(eV)}^2 $, $m_2^2 \simeq 0.01 \, \mbox{(eV)}^2 $, $m_3^2 \simeq (1.5 - 1) \times 10^{-4} \mbox{(eV)}^2 $.…
It is shown that the simplest breaking of the subnuclear democracy leads to a successful description of the mixing between the second and third family. In the lepton channel the nu_mu - nu_tau -oscillations are expected to be described by a…
A minimal extension of the standard model to naturally generate small neutrino masses and provide a dark matter candidate is proposed. The dark matter particle is part of a new scalar doublet field that plays a crucial role in radiatively…
In this talk I review our present knowledge on neutrino masses and mixing trying to emphasize the most direct implications and challenges of these results.
In the first part of these lectures the neutrino mixing hypothesis will be considered in detail. We will discuss the possible schemes of neutrino mixing and present the data of the recent experiments searching for effects due to…
The Standard Model of particle physics describes neutrinos as massless, chargeless elementary particles that come in three different flavours. However, recent experiments indicate that neutrinos not only have mass, but also have multiple…
We account for the solar and atmospheric neutrino problems by introducing maximal mixing between conventional and sterile neutrino partners. We achieve this by invoking a seesaw-like mechanism which not only provides us with maximally mixed…