Finite Unification and Top Quark Mass †

In unified gauge theories there exist renormalization group invariant relations among gauge and Yukawa couplings that are compatible with perturbative renormalizability, which could be considered as a Gauge-Yukawa Unification. Such relations are even necessary to ensure all-loop finiteness in Finite Unified Theories, which have vanishing βfunctions beyond the unification point. We elucidate this alternative way of unification, and then present its phenomenological consequences in SU(5)-based models. On leave of absence from College of Liberal Arts, Kanazawa Univ., Japan Partially supported by C.E.U. projects (SC1-CT91-0729;CHRX-CT93-0319). † Presented by G. Zoupanos at the 27th International Conference on High Energy Physics, Glasgow, 20-27th July 1994, to appear in the proceedings.