SLAC SUMMER INSTITUTE 1997 PHYSICS OF LEPTONS |
August 4-15, 1997
Stanford Linear Accelerator Center
Stanford, California, U.S.A.
From J. J. Thomson's identification of cathode rays as electrons a century ago, to I. I. Rabi's exclamation, "O.K., who ordered the muon?" to Martin Perl's interpretation of anomalous electron-muon events as taus, leptons have formed the vanguard of the elementary particle spectrum. Each discovery has ushered in a new generation with new complexity. We turn our attention at this year's Summer School to the leptons, and highlight their unique and varied roles in particle physics. In the neutrino sector, masses and mixing angles are now being probed by experiments with a variety of neutrino sources, including the sun, cosmic rays, reactors, and accelerators. Neutrinos also play an important role in cosmology. The puzzle posed by the charged leptons lies in the large difference in their masses, coupled with the precise universality of their interactions and decays. We still await an answer to Rabi's question!