相关论文: Atmospheric \nu_\mu Deficit from Decoherence
The modern picture of the neutrino as a multiple mass highly mixed neutral particle has emerged over 40 years of study. Best known of the issues leading to this picture was the apparent loss of neutrinos coming from the sun. This article…
If neutrino oscillation plays a role in explaining the atmospheric neutrino deficit, then the same phenomenon would necessarily affect also the dark matter indirect-detection signal which consists in a muon-neutrino flux produced by…
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…
In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the…
It is argued that the observed deficit of solar and atmospheric neutrinos can be explained by neutrino oscillations $\nu_e \to \nu_s $ and $\nu_\mu \to \nu'_{s}$ involving two hypothetic sterile neutrinos $\nu_s $ and $\nu'_{s} $ (blind to…
We note a discrepancy between the value of R expected on the basis of the muon neutrino angular distribution and the value actually observed. The energy independence of $R$ leads to a fine tuning problem. This may be indicative of some…
Atmospheric neutrinos produced by cosmic-ray interactions around the globe provide a beam for the study of neutrino properties. They are also a background in searches for neutrinos of astrophysical origin. Both aspects are addressed in this…
It is shown that the results of the Super-Kamiokande atmospheric neutrino experiment, interpreted in terms of nu_mu<--->nu_tau flavor transitions, can probe possible decoherence effects induced by new physics (e.g., by quantum gravity) with…
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…
MACRO can detect three topologies of neutrino induced events, corresponding to different parent neutrino energies. The most numerous sample is made of upward throughgoing muons induced by atmospheric neutrinos of average energy 100 GeV. We…
The favoured resolution of the atmospheric neutrino anomaly involves an oscillation of the muon neutrino to a different state. Current experiments allow for the latter to contain a significantly large fraction of a non-standard flavour. We…
High-energy neutrinos, arising from decays of mesons that were produced through the cosmic rays collisions with air nuclei, form unavoidable background noise in the astrophysical neutrino detection problem. The atmospheric neutrino flux…
The three neutrino mass matrices in the $SU(5)\times U(2)$ model are studied focusing on the neutrino oscillation experiments. The atmospheric neutrino anomaly could be explained by the large $\nu_{\mu} - \nu_{\tau}$ oscillation. The long…
In this talk I review the present status of the atmospheric neutrino anomaly and discuss some solutions that have been presented in the literature to solve this problem. In particular I review the "standard" solution in terms of neutrino…
We examine the uncertainty of the calculation of the atmospheric neutrino flux and present a way to reduce it using accurately measured atmospheric muon flux. Considering the difference of the hadronic interaction model and the real one as…
The discovery of the missing atmospheric muon neutrinos known as the atmospheric neutrino anomaly, is briefly described. Learned and Lipari gave a general review of atmospheric neutrinos at the conference, including the discovery of the…
The flux of muons induced by atmospheric neutrinos has been measured with the MACRO detector. Different event topologies have been detected, due to neutrino interactions in the apparatus and in the rock below it. The upward-throughgoing…
We consider a solution of the atmospheric neutrino problem based on oscillations of muon neutrinos to sterile neutrinos: $\nu_{\mu}$ $\leftrightarrow$ $\nu_s$. The zenith angle ($\Theta$) dependences of the neutrino and upward-going muon…
The data on atmospheric neutrinos can be explained assuming the existence of oscillations between muon neutrinos and light sterile neutrinos with mixing close to maximal, and Delta_m^2 approximately equal to 3 E-3 (eV^2). This…
Since evidence for neutrino oscillations was first observed in 1998, the study of muon neutrino oscillations has been aggressively pursued. In doing so, atmospheric and accelerator-based neutrino experiments have measured with the highest…