Signatures of Technicolor Models with the GIM Mechanism

Abstract

We investigate the production and the decays of pseudo-Goldstone bosons (PGBs) predicted by technicolor theories with the GIM mechanism (TC-GIM). The TC-GIM models contain exotic fermion families that do not interact under weak $SU(2)$, but they do have color and hypercharge interactions. These fermions form PGBs, which are the lightest exotic particles in the TC-GIM models. The spectrum of PGBs consists of color octets, leptoquarks and neutral particles. The masses of leptoquarks and color octets depend on a free parameter - the scale of confining interactions. Characteristic for TC-GIM models is a very light (approx 1 GeV) neutral particle with anomalous couplings to gauge boson pairs. We show how current experiments constrain the free parameters of the models. The best tests are provided by the pp --> TT and e^+e^- --> P^0 gamma reactions. Experiments at LHC and NLC can find PGBs of TC-GIM models in a wide range of parameter space. However, TC-GIM models can be distinguished from other TC models only if several PGBs are discovered.