ABSTRACT

Neutrino physics has experienced quite a significant boost in recent years with the establishment of a non-vanishing rest mass of the neutrino. As discussed in more detail in the corresponding chapters, all evidence stems from neutrino oscillation searches. There are three pieces of evidence:

• A deficit in upward-going muons produced by atmospheric neutrinos. This can be explained by νµ oscillations with m2 ≈ 3 × 10−3 eV2 and sin2 2θ ≈ 1 very likely into ντ .