Is the Top Quark Really Heavier than the $W$ Boson?

Abstract

Scalar induced top decays may drastically suppress $B(t\to \ell \nu +jet)$ and still hide the top below $M_W$. The $p\bar{p}$ collider experiments should enlarge the scope and study the $m_t-B(t\to \ell \nu j)$ plane. Specific model signatures such as $t\to c{h}^0\to cb\bar{b}$ (multiple high $p_T$ $b$-jets) and $t\to b{H}^{+}\to bc\bar{s}$, $b{\tau }^{+}\nu$ (with B(t\to b\tau\nu) \ \raisebox{-.5ex}{\rlap{\sim}} \raisebox{.4ex}{<}\ 1/3) should be explored. Without ruling out these possibilities, isolated lepton signals in the future might actually be due to the 4th generation $t^{\prime }$ or $b^{\prime }$ quark, while top quark and toponium physics could still turn up at LEP-II.

Comments: 11 pages (RevTex), 3 figures (not included), NTUTH-93-09