Speaker
Description
In the SO(10) GUTs with or without supersymmetry, the third-generation fermions' Yukawa couplings can be unified by employing renormalization group (RG) analysis, similar to the gauge couplings. In the considered models, Yukawa unification implies that different Yukawa couplings are generated from a single coupling in the UV through the decomposition of scalar and fermion representations of the GUT group. Thus, the Yukawa hierarchy emerges from the CG coefficient of decomposition of the GUT group and vacuum expectation values (vevs) of different scalars. Previous research has examined the realization of Yukawa unification in supersymmetric SO(10) models. In this talk, we will present a non-supersymmetric SO(10) model with an intermediate Pati-Salam symmetry scale, where both gauge and Yukawa unification can be achieved simultaneously. Then, as an example, we show that the Yukawa unification in the SO(10) model can be obtained from an $E_6$ model where the two SO(10) scalar multiples belong to a single $E_6$ multiple. By considering phenomenological constraints such as the proton decay and the absence of flavor-changing neutral currents at tree-level, we can obtain a phenomenologically acceptable model. By RG flows to the IR scale, we show that Yukawa unification implies a constraint on the parameter space of the low-energy 2HDM, specifically, to the ratio of the vevs of the two Higgs doublets at the electroweak scale, referred to as $\tan \beta$.
