Seesaw mechanism and Weinberg operator

Based on the following papers, Manuel González López will present the seesaw mechanism and the Weinberg operator.

Baryon- and Lepton-Nonconserving Processes (Steven Weinberg, Phys. Rev. Lett. 43, 1566 (1979)):

A number of properties of possible baryon- and lepton-nonconserving processes are shown to follow under very general assumptions. Attention is drawn to the importance of measuring μ+ polarizations and v̄e/e+ ratios in nucleon decay as a means of discriminating among specific models.

Horizontal Symmetry and Masses of Neutrinos (Tsutomu Yanagida, Prog. Theor. Phys. 64, 1103 (1980)):

Assuming a horizontal symmetry SUF(n), we demonstrate a possibility that the left-handed neutrinos receive masses of order 1eV, which is consistent with recent experiments on neutrino oscillations. The smallness of the neutrino masses is an indication of a large breaking of the horizontal symmetry.