SU(5)-Compatible Yukawaon Model

TL;DR

This paper explores constraints on the yukawaon model within an SU(5) framework, proposing a cutoff-free approach with vector-like fields and analyzing symmetry breaking at high energy scales.

Contribution

It introduces a yukawaon model compatible with SU(5) without a cutoff scale by adding vector-like fields and examines the implications of U(3) family symmetry breaking.

Findings

Yukawaon effective couplings derived from VEVs of new fields.

Model achieves SU(5) compatibility with high-scale symmetry breaking.

Eliminates need for cutoff scale in yukawaon models.

Abstract

It is investigated what constraints are imposed on the so-called yukawaon model when we regard quarks and leptons as $(\bar{\bf 5}_i+{\bf 10}_i+{\bf 1}_i)$ 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 $(\bar{\bf 5}^i+{\bf 10}^i+{\bf 5}_i +\bar{\bf 10}_i)$ are introduced in addition to the conventional quarks and leptons. The U(3) family symmetry is broken at $<Y_f>\sim 10^{13}$ GeV.