Standard Model Couplings with ${\alpha }^{-1}=137\pm 9$ from Multiple Point Criticality and 3 Generations of Gauge Bosons: No GUT, No SUSY

Abstract

We consider the application of the Multiple Point Criticality Principle to the Standard Model and its extension to the anti-grand gauge group $SM{G}^3\otimes U(1{)}_f$ at the Planck scale. In particular we discuss the predictions for the fine structure constants: ${\alpha }^{-1}(0)=137\pm 9$, ${\alpha }_1^{-1}(M_Z)=99\pm 5$, ${\alpha }_2^{-1}(M_Z)=29\pm 6$, ${\alpha }_3^{-1}(M_Z)=12\pm 6$. We also present our Standard Model predictions for the top quark and Higgs masses and a $SM{G}^3\otimes U(1{)}_f$ fit of the quark-lepton masses and mixing angles. We characterise $SM{G}^3\otimes U(1{)}_f$ as the largest possible extension of the Standard Model gauge group satisfying some relatively simple assumptions. The resolution of some other fine-tuning problems (${\Lambda }_{cosmological}$, ${\Theta }_{QCD}$, $M_{Higgs}$) by the multiple point requirement of degenerate vacua is briefly discussed.

Comments: uuencoded 4 page LaTeX file, uses stwol.sty; published in Proceedings of 28th International Conference on High Energy Physics (ICHEP 96), Warsaw: 1646-1649