Introduction, formalism, and cosmological bound

In these four lectures I will present a brief and rather elementary description of the physics of massive neutrinos as it emerges from studies involving nuclear physics, particle physics, astrophysics and cosmology. The lectures are meant for physicists who are not experts in this field, which I believe covers most of the participants in this School, and many potential readers elsewhere. I hope that such readers can find here enough information that they will be able to understand and appreciate the connection between the hunt for neutrino mass and mixing described here, and their own field of expertize.

Throughout I will use original references sparingly. Instead I refer to several monographs, written and published during the last decade [Boehm & Vogel (1992), Kayser, Gibrat–Debu k Perrier (1989), Winter (1991), Mohapatra & Pal (1991), Kim & Pevsner (1993), Klapdor–Kleingrothaus & Staudt (1995)] where an interested reader can find references to the original papers. When appropriate I will also refer to review papers on various aspects of the neutrino mass or related topics. For the experimental data, including the list of the most recent original experimental papers, the best source is the Review of Particle Physics, periodically updated, with the latest printed version in PDG (1996). The update of this very useful publication is available even between printed editions on the World–Wide Web at http://pdg.lbl.gov/.