Yukawa ratio predictions in non-renormalizable SO(10) GUT models

Abstract

Since SO(10) GUTs unify all fermions of the Standard Model plus a right-chiral neutrino in a representation 16 per family, they have the potential to be maximally predictive regarding the ratios between the masses (or Yukawa couplings) of different fermion types, i.e. the up-type quarks, down-type quarks, charged leptons and neutrinos. We analyze the predictivity of classes of SO(10) (SUSY) GUT models for the fermion mass ratios, where the Yukawa couplings for each family are dominated by a single effective GUT operator of the schematic form 16 2 · 45 n · 210 m · H, for H ∈ {10, 120, 126}. This extends previous works to general vacuum expectation value directions for GUT-scale VEVs and to larger Higgs representations. In addition, we show that the location of the MSSM Higgses in the space of all doublets is a crucial aspect to consider. We discuss highly predictive cases and illustrate the predictive power in toy models consisting of masses for the 3rd and 2nd fermion family.

Employing nucleon decay as a fingerprint of SUSY GUT models using SusyTCProton

“…For each model we assume a particular texture of Yukawa matrices, to be specified later, and single operator dominance in each Yukawa entry, i.e. only a single GUT operator is present or dominates every Yukawa entry (see [22][23][24][25][26] for concrete realizations in the literature). This imposes strict relations between different fermion sectors and increases model predictivity.…”

Nucleon decay in a minimal non-SUSY GUT with predicted quark-lepton Yukawa ratios

“…Examples for models realizing single operator dominance this way can e.g. be found in [14][15][16][17][18]. In the following we will further assume that the applied family symmetry also makes sure that 45 H only couples to the 22 entry of Y 5 .…”

“…They have been discussed in the context of SUSY GUTs in [14,31]. We assume for both models single operator dominance in each entry [14][15][16][17][18], including now also the first family of quarks and leptons. For the neutrino sector in model 1 and model 2 we choose the CSD2 [40,41] and CSD3 [42] texture, respectively.…”

“…These gauge bosons3 The concept of single operator dominance has so far mainly been studied in the context of SUSY GUTs, cf. e.g [14][15][16][17][18],. but is rarely considered in the context of non-SUSY GUTs.…”

Viable quark-lepton Yukawa ratios and nucleon decay predictions in $SU(5)$ GUTs with type-II seesaw

“…They have in common that only a single GUT operator dominates each relevant entry in the GUT Yukawa matrices, a concept we refer to as single operator dominance (cf. [17][18][19]). Different types of GUT operators can result in different GUT predictions for the respective quark-lepton Yukawa ratio.…”