SU(5)-Compatible Yukawaon Model

Abstract

It is investigated what constraints are imposed on the so-called yukawaon model when we regard quarks and leptons as $({\bar{5}}_i+{10}_i+1_i)$ of SU(5) ($i=1,2,3$: index of U(3) family symmetry). In past yukawaon models, the effective Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values of fields $Y_f$ ("yukawaons") as $(Y_f^{eff}{)}_{ij}=(y_f/\Lambda )<(Y_f{)}_{ij}>$. In order to build a model without a cutoff scale $\Lambda$, vector-like fields $({\bar{5}}^i+{10}^i+5_i+{\overline{10}}_i)$ are introduced in addition to the conventional quarks and leptons. The U(3) family symmetry is broken at $<Y_f>\sim 10^{13}$ GeV.

Comments: 13 pages, 1 fugure, minor improvements