This book constitutes the proceedings of an up-to-date and comprehensive meeting devoted to the question whether baryon number violation can occur — in the standard model of weak and electromagnetic interactions — at rates which can be relevant to cosmology and particle experiment. There has been a great deal of activity and many new results in the past year, and the meeting was the first occasion for a review of the field. It is the only source in which all the work in this field is reviewed in a single volume. As such, it would provide a useful reference for graduate students and researchers wanting to learn more about this area.

Bringing together leading researchers from particle physics, astrophysics, and cosmology, Lepton and Baryon Number Violation in Particle Physics, Astrophysics and Cosmology presents reviews of current theoretical ideas, experimental results, and future perspectives in this topical field. The book covers areas related to baryon number (B) and lepton

It has recently been realized that Baryon Number, a fundamental symmetry in all observed high energy physics reactions, is NOT exactly conserved in the STANDARD ELECTROWEAK (WEINBERG-SALAM) THEORY, at energies of order 10 TeV or higher. This raises the tantalizing possibility of DIRECTLY PRODUCING BARYON NUMBER VIOLATING PROCESSES IN THE NEW GENERATION OF PARTICLE ACCELERATORS, such as the SSC. The Santa Fe Workshop on Baryon Number Violation at the SSC is the first Workshop to bring together experts in the subject to address the very interesting theoretical issues in non-perturbative field theory that need to be settled in order to decide if this possibility may actually be realized.

In the presence of rapid fermion-number violation due to nonperturbative electroweak effects certain relations between the baryon number of the Universe and the lepton numbers of the Universe are predicted. In some cases the electron-neutrino asymmetry is exactly specified in terms of the baryon asymmetry. Without introducing new particles, beyond the usual quarks and leptons, it is necessary that the Universe possess a nonzero value of B - L prior to the epoch of fermion-number violation if baryon and lepton asymmetries are to survive. Contrary to intuition, even though electroweak processes violate B + L, a nonzero value of B + L persists after the epoch of rapid fermion-number violation. If the standard model is extended to include lepton-number violation, for example through Majorana neutrino masses, then electroweak processes will reduce the baryon number to zero even in the presence of an initial B - L unless 20 M(sub L) approximately greater than the square root of (T(sub B - L) m(sub P1)) where M(sub L) sets the scale of lepton number violation and T(sub B - L) is the temperature at which a B - L asymmetry is produced. In many models this implies that neutrinos must be so light that they cannot contribute appreciably to the mass density of the Universe. Harvey, Jeffrey A. and Turner, Michael S. NASA-CR-186609, NAS 1.26:186609, FERMILAB-PUB-90/49-A, EFI-90-33 NSF PHY-86-58033; NAGW-1340...