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.

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