Fermion Mass Postdictions in a Generalized Extended Technicolour Scenario

Abstract

We review the recent discussion in the literature of one family extended technicolour models with techni-fermion mass spectra compatible with the experimental data for the precision parameters S,T,U,V, W and X and ETC interactions compatible with the LEP measurements of the $Z\to b\bar{b}$ vertex. To investigate whether these scenarios are consistent with the third family fermion masses we develop a generalized ETC model in which ETC interactions are represented by four Fermi interactions. We discuss in detail the reliability of the gap equation approximation to the non-perturbative dynamics. Two generic scenarios of couplings fit the precision data and third family masses; one is an unpredicitive existence proof, the other, which generates the large top mass by direct top condensation, has a minimal number of interactions that break the global symmetry of the light fermions in the observed manner. This latter scenario makes surprisingly good predictions of the charm, strange and up quark masses.

32 pages + 9 pages with figures, ps

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Cited by in corpus (1)

• Multiscale Technicolor and the Zbb-bar Vertex