Adding singlet neutrinos to the standard model spectrum in general gives rise to Z-induced flavor-changing neutral currents. We study the impact of these currents on matter-induced neutrino oscillations in the sun and in supernovae. While the effects for solar neutrinos are negligible, dramatic effects are possible for supernova neutrinos.

The results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ∼ 4 and ∼ 50 GeV. The Multiple Coulomb Scattering of muons in the MACRO absorbers was used to estimate the neutrino energy of each event of the higher energy sample. The angular distributions, the absolute fluxes and ...

Because the propagation of neutrinos is affected by the presence of Earth matter, it opens new possibilities to probe the Earth’s interior. Different approaches range from techniques based upon the interaction of high energy (above TeV) neutrinos with Earth matter, to methods using the MSW effect on the neutrino oscillations of low energy (MeV to GeV) neutrinos. In principle, neutrinos from man...

We study the potential benefits of an iodine-based solar–neutrino detector for testing hypotheses that involve neutrino oscillations. We argue that such a detector will have a good chance of distinguishing the two allowed regions of ∆m – sin 2θ parameter space if neutrino conversion is occurring in the sun. It should also be able to detect seasonal variations in the signal due to vacuum oscilla...

Because the propagation of neutrinos is affected by the presence of Earth matter, it opens new possibilities to probe the Earth’s interior. Different approaches range from techniques based upon the interaction of high energy (above TeV) neutrinos with Earth matter, to methods using the MSW effect on the oscillations of low energy (MeV to GeV) neutrinos. In principle, neutrinos from many differe...

A statistical analysis of coronal loop oscillations observed by TRACE shows that 12 of 28 cases were associated with metric type II bursts. The timing is consistent with the idea that the loop oscillations in many cases result from the passage of a large-scale wave disturbance originating in a flare in the nearby active region. The GOES classifications for these flares range from C4.2 to X20. T...

Observations of transversal coronal loop oscillations very often show the excitation and damping of oscillations in groups of coronal loops rather than in individual and isolated structures. We present results on the oscillatory properties (periods, damping rates, and spatial distribution of perturbations) for resonantly damped oscillations in a system of two inhomogeneous coronal slabs and com...

Using the local helioseismic technique of ring diagram we analyze the frequencies of high–degree fand p-modes derived from both velocity and continuum intensity data observed by MDI. Fitting the spectra with asymmetric peak profiles, we find that the asymmetry associated with velocity line profiles is negative for all frequency ranges agreeing with previous observations while the asymmetry of t...

If the lepton numbers are associated to global symmetries spontaneously broken at a scale below 1 TeV, neutrino oscillations in Supernovae produce classic Majoron fields that perturb the neutrino propagation itself and may change the oscillation patterns in the periods of largest ν fluxes. The impact of the Majoron fields on the same transitions as νe → νX that presumably occur in the Sun is st...

Exact analytical expressions in terms of generalized confluent hypergeometric functions for the transition amplitudes of neutrino oscillations in presence of matter are computed for an arbitrary number of species. The density of matter is assumed to be exponentially decaying. The results can be used for the description of matter-induced neutrino oscillations in the Sun which can take place when...