Discovery of Atmospheric Neutrino Oscillations (<Special Issue>Physics of Neutrino - Commemorating Masatoshi Koshiba's Winning of the Nobel Prize in Physics -)

Abstract

Cosmic ray particles entering the atmosphere interact with the air nuclei and produce neutrinos. These neutrinos are called atmospheric neutrinos. The atmospheric neutrino anomaly observed in Kamiokande is now understood as due to neutrino oscillations by high statistics measurements of the atmospheric neutrinos in Super-Kamiokande. The studies of the atmospheric neutrinos have matured into detailed studies of neutrino masses and mixings.