Renormalization Group Fixed Point with a Fourth Generation: Higgs-induced Bound States and Condensates

Abstract

In the Standard Model with four generations, the two-loop renormalization group equations for the Higgs quartic and Yukawa couplings have a fixed point structure. If the masses of the fourth family are sufficiently heavy, it will contain a natural scale $\Lambda_{FP}$ in the range of a few TeV to the order of $10^2$ TeV, above which the Higgs quartic and Yukawa couplings become practically constant. We found that around $\Lambda_{FP}$ the strong Yukawa couplings make it possible for the fourth generation to form bound states, including composite extra Higgs doublets. In this scenario the fourth generation condensates are obtained without introducing Technicolor or other unknown interactions.