Phenomenology of atmospheric neutrinos

TL;DR

This paper discusses how data on upward-going muons support neutrino oscillations as the explanation for atmospheric neutrino anomalies, and helps differentiate between various oscillation models and exotic theories.

Contribution

It emphasizes the importance of upward-going muon data in confirming neutrino oscillations and excluding alternative explanations for atmospheric neutrino observations.

Findings

Supports neutrino oscillation hypothesis

Excludes simple neutrino decay and exotic models

Differentiates between oscillation channels based on matter effects

Abstract

The relevance of the data concerning upward--going muons for the solution of the atmospheric neutrino problem is stressed. In particular, their inclusion in the analysis confirms the goodness of the neutrino oscillation hypothesis and allows to exclude some alternative, exotic explanations such as neutrino decay, flavour changing neutral currents, violations of the equivalence principle (at least in their simplest forms), and also to discriminate, in principle, between different neutrino oscillation models (nu_mu <-> nu_tau versus nu_mu <-> nu_s), because of the difference in the matter effects.