Minimal SU(5) Resuscitated by Higgs Coupling Fixed Points

Abstract

The issue of gauge unification in the (non-supersymmetric) Standard Model is reinvestigated. It is found that with just an additional fourth generation of quarks and leptons, $SU(3)\otimes SU(2)\otimes U(1)$ gauge couplings converge to a common point $\sim 2.65\times 10^{15}$ GeV (${\tau }_p\sim 10^{34\pm 1}$ years) provided the Higgs boson has a mass of at least 210 GeV. The presence of ultraviolet fixed points for the Yukawa and Higgs quartic couplings is found to be the origin of such unification.

13 pages, RevTex, 1 ps Figure (missing figure now included)