On the spin-zero partners of composite weak bosons

The dynamics and some phenomenological implications of the spin-zero partners of the W-bosons, which can couple to fermion pairs a la Higgs (π-tilde) or in an universal way (U, X) are studied. A light hyperpion π-tilde decouples in low-energy weak-interaction physics in contrast to the pion in hadronic interactions. The best signal for the π-tilde is its copious pair production in W or Z decays with a width of the order of 0.25 GeV. A 50 GeV mass of these bosons can be explained with a relatively light value of the preon ''current'' mass. A strong coupling for the Z-X-γ vertex and a weak one for the Z-e+e- are dynamically consistent. A present rate of Z into γe+e- would correspond to a X total width of the order of 0.24 GeV