NARROW-RESONANCE IN e e SCATTERING DUE TO ADDITIONAL GAUGE BOSON

It now appears phenomenologically that the third family may be essentially diierent from the rst two. Particularly the high value of the top quark mass suggests a special role. In the standard model all three families are treated similarly becoming exactly the same at asymptotically high energies] so I need to extend the model to accommodate the goal of a really diierent third family. In this article I describe one such viable extension, the 331 model which predicts bileptonic gauge bosons. In this presentation, I shall describe the 331 Model and elaborate on its predictions including the bilepton I use the new terminology \bilepton" to distinguish from \dilepton" which is used by experimentalists with a rather diierent meaning], the neutrino masses and tests in hadronic and leptonic colliders. 331 Model Family symmetry is usually taken to mean a horizontal symmetry, either global or gauged, under which the three families transform under some non-trivial representation. The family symmetry is broken in order to avoid unobserved mass degeneracies. In this meaning of family symmetries, there is usually no explanation of why there are three families which are the input. Rather the hope is that the postulated family symmetry may explain the observed hierarchies: m u m c m t m d m c m b 13 < 23 < 12 : (1) In the present model, the aim of family symmetry is indeed to attempt to address such hierarchies and to explain why there are three families. This may be a necessary rst step to understanding hierarchies? To introduce the 331 Model 1 the following are motivating factors: i) Consistency of a gauge theory (unitarity, renormalizability) requires anomaly cancelation. This requirement almost alone is able to x all electric charges and other quantum numbers within one family of the standard model. This accounts for charge quantization, e.g. the neutrality of the hydrogen atom, without the need for a GUT.