Cosmic rays was the birthplace of elementary particle physics.
The discovery of the positron, of the muon, pion, kaon and many
baryons paved the way for the development of the standard model
of particle physics. The observation of neutrino oscillations in cosmic
rays, which implied non-zero neutrino masses lead to physics
beyond the standard model. Whether cosmic rays can contribute to
the understanding of the nature of the dominating non-baryonic