Is $M_t\simeq M_w$ Ruled Out?

Abstract

A four generation supersymmetric model is proposed, in which the Tevatron ``top-quark'' events are reinterpreted as the production of $t^\prime$ which decays dominantly to $bW^+$. In this model, $m_t\simeq m_W$, and $t\rta\widetilde t\widetildeχ^0_1$, with $\widetilde t\rta c\widetildeχ^0_1$. This decay chain, which rarely produces a hard isolated lepton, would have been missed in all previous top quark searches. A narrow region of the model parameter space exists which cannot yet be ruled out by present data. This model predicts a rich spectrum of new physics which can be probed at LEP-II and the Tevatron.