Atmospheric Neutrinos

Abstract

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 chapter, which begins with a brief introduction on neutrino oscillations in relation to the spectrum of atmospheric neutrinos. Section 2 describes the cascade equation for hadrons in the atmosphere and the main features of atmospheric leptons from their decays. Next, uncertainties in the fluxes that arise from limited knowledge of the primary spectrum and of particle production are discussed. The final section covers aspects specific to neutrino telescopes.