Negative T from a dynamical left-handed neutrino mass

Abstract

We show how a dynamical Majorana mass for a fourth family left-handed neutrino can make a significant negative contribution to the electroweak correction parameter T without making a large contribution to S or U. We also comment on other possible contributions to T in the context of dynamical symmetry breaking.

Comments: 8 pages, postscript, version to be published as Rapid Communications in PRD, PDF file is available at http://miteymac.physics.utoronto.ca/bh/papers/papers.html