相关论文: The east-west effect for atmospheric neutrinos
The east-west anisotropy, caused by the deflection of primary cosmic rays in the Earth's magnetic field, is observed for the first time in the flux of atmospheric neutrinos. Using a 45 kt-year exposure of the Super-Kamiokande detector, 552…
Observations of atmospheric neutrinos by the SuperKamiokande collaboration have demonstrated large mixing of the muon-neutrino. However the present atmospheric neutrino data does not significantly constrain the associated mixing of the…
The uncertainty in the calculation of atmospheric neutrino fluxes is studied. The absolute value of atmospheric neutrino fluxes is sensitive to variation of the primary cosmic ray flux model and/or the interaction model. However, the ratios…
Geomagnetic effects distort the zenith angle distribution of sub--GeV and few--GeV atmospheric neutrinos, breaking the up--down symmetry that would be present in the absence of neutrino oscillations and without a geomagnetic field. The…
We compute up-down asymmetries for atmospheric neutrino induced electron and muon events in the SuperKamiokande detector for the following neutrino oscillation models: (A) maximally mixed $\nu_{\mu} - \nu_{\tau}$ or $\nu_{\mu} - \nu_s$, (B)…
This talk reports the latest indications of an anomaly in the measurements of atmospheric neutrinos. New results from Soudan-2 and Super-Kamiokande provide evidence that the ratio of nu_mu to nu_e interactions is not as expected. High…
In this talk I review measurements and calculations of the flux of neutrinos produced by interactions of cosmic rays in the atmosphere. The main reason for interest in this subject is the apparent anomaly between the predicted and the…
An evaluation of the principal uncertainties in the computation of neutrino fluxes produced in cosmic ray showers in the atmosphere is presented. The neutrino flux predictions are needed for comparison with experiment to perform neutrino…
The atmospheric neutrino beam simultaneously spans a range of pathlengths from ten to ten thousand kilometers, which correspond respectively to downward- and upward-going neutrinos. As with any neutrino oscillation experiment, also in this…
The zenith angle distributions of atmospheric neutrinos are determined by the possible presence of neutrino oscillations and the combination of three most important contributions: (1) geomagnetic effects on the primary cosmic rays, that…
The atmospheric neutrino anomaly is the apparent reduction of the $\nu_{\mu}/\nu_{e}$ ratio observed in underground detectors. It represents either a reduction in the muon neutrino interaction rate or an excess of the electron neutrino…
This review of atmospheric muons and neutrinos emphasizes the high energy range relevant for backgrounds to high-energy neutrinos of astrophysical origin. After a brief historical introduction, the main distinguishing features of…
Earth medium effects in the three-neutrino oscillations of atmospheric neutrinos are observable under appropriate conditions. This paper generalizes the study of the medium effects and the possibility of their observation in the atmospheric…
The atmospheric muon and neutrino flux have been simulated using the same approach which successfully accounted for the recent secondary proton, electron and positron flux measurements in orbit by the AMS experiment. For the muon flux, a…
Motivated by recent results from SuperKamiokande, we study both solar and atmospheric neutrino fluxes in the context of oscillations of the three known neutrinos. We aim at a global view which identifies the various possibilities, rather…
We present a new one-dimensional calculation of low and intermediate energy atmospheric muon and neutrino fluxes, using up-to-date data on primary cosmic rays and hadronic interactions. We study several sources of uncertainties relevant to…
The symmetry of the problem of the apparent deficit in upward-going atmospheric muon neutrinos reveals two possible, nonexclusive kinds of solution: Nonlinearity in distance or nonlinearity in angle of observation. Nonlinearity in distance…
We suggest that the atmospheric neutrino anomaly observed in the Super-Kamiokande (and other) experiments results from the combined effects of muon-neutrino to tau-neutrino oscillations with a Delta m^2 value of approximately 0.4 eV^2 and…
A Monte-Carlo calculation of the atmospheric neutrino fluxes [1,2] has been extended to take account of the three-dimensional (3D) nature of the problem, including the bending of secondary particles in the geomagnetic field. Emphasis has…
The simplest explanation for the atmospheric neutrino anomaly is the transition of muon neutrinos and antineutrinos into states of different flavor. Data from the reactor experiment Chooz, and the measurement of the energy and angle…