MIRROR FAMILIES IN ELECTROWEAK SYMMETRY-BREAKING

We study symmetry breaking in a left-right symmetric extension of the Standard Model with mirror fermions, one for each Standard-Model fermi on. The new particles assist a top-quark condensate in breaking electr o-weak symmetry, Half of the fermions acquire electro-weak-invariant m asses at around 500 GeV and would be probably accessible at future hig h-energy experiments like LHC or NLC. The contributions to the S and T parameters are small and negative in accordance with electro-weak pre cision data. (C) 1998 Elsevier Science B.V. All rights reserved.