相关论文: Analytical description of the Day-Night neutrino a…
In the 3-flavour framework we derive a simple approximate analytic expression for the day-night difference of the flux of solar $\nu_e$ at terrestrial detectors which is valid for an arbitrary Earth density profile. Our formula has the…
The Earth's density distribution can be approximately considered piecewise continuous at the scale of two-flavor oscillations of typical solar neutrinos, such as the beryllium-7 and boron-8 neutrinos. This quite general assumption appears…
We discuss various aspects of the solar neutrino spectrum distortion and time variations of fluxes. (i) Oscillations of neutrinos which cross the mantle and the core of the Earth can be parametrically enhanced. The parametric effect gives…
We analyze peculiar effects in the day-night asymmetry of solar neutrinos taking place due to their continuous observation during the night and/or the year. Namely, we show that the day-night effect contains both a trivial, cumulative…
We investigate the effects of a nonzero leptonic mixing angle $\theta_{13}$ on the solar neutrino day-night asymmetry. Using a constant matter density profile for the Earth and well-motivated approximations, we derive analytical expressions…
Day-night asymmetries in active-sterile solar neutrino oscillations are discussed in the general $3+N_{s}$ mixing framework with three active and N_s sterile neutrinos. Analytical expressions of the probability of neutrino flavor…
A qualitative understanding of the day-night asymmetry for solar neutrinos is provided. The greater night flux in nu_e is seen to be a consequence of the fact that the matter effect in the sun and that in the earth have the same sign. It is…
We consider the day-night asymmetries predicted by MSW solutions of the solar neutrino problem. The integration over the neutrino energy, as well as over the production region or over the time intervals of more than a day leads to the…
We derive an analytical description of neutrino oscillations in matter based on the Magnus exponential representation of the time evolution operator. Our approach is valid in a wide range of the neutrino energies and properly accounts for…
We analyze the peculiar seasonal effects in the day-night asymmetry of solar neutrinos, namely those connected with the neutrino nighttime flux anomaly near the winter solstice. We show that, for certain placements of the neutrino detector,…
It is shown that the strong enhancement of the Earth (day-night) effect for solar neutrinos crossing the Earth core in the case of the small mixing angle MSW electron neutrino to muon (tau) neutrino transition solution of the solar neutrino…
We present a formalism for the matter effects in the Earth on low energy neutrino fluxes which is both accurate and has all advantages of a full analytic treatment. The oscillation probabilities are calculated up to second order term in…
A set of quantitative predictions for the day-night asymmetry in the Super - Kamiokande detector is presented. For these predictions, neutrino events are collected in ``samples'' defined by the trajectories in the Earth of the corresponding…
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…
We study in details the Earth matter effects on the boron neutrinos from the Sun using recently developed 3D models of the Earth. The models have a number of new features of the density profiles, in particular, a substantial deviation from…
It has been stated in the literature that the case of maximal mixing angle for \nu_e leads to no day-night effect for solar neutrinos and an energy independent flux suppression of 1/2. While the case of maximal mixing angle and \Delta m^2…
The Earth effects on the energy spectra of supernova neutrinos are studied. We analyze numerically the time-integrated energy spectra of neutrino in a mantle-core-mantle step function model of the Earth's matter density profile. We consider…
We study the matter effects for solar neutrino oscillations in a general scheme, without any constraint on the number of sterile neutrinos and the mixing matrix elements, only assuming a realistic hierarchy of neutrino squared-mass…
We give a perturbation theory of neutrino oscillation in the Earth. The perturbation theory is valid for neutrinos with energy $E \gsim 0.5$ GeV. It is formulated using trajectory dependent average potential. Non-adiabatic contributions are…
We report an indication that the elastic scattering rate of solar $^8$B neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through the Earth during nighttime. We determine the day/night asymmetry,…