Model Building with Gauge-Yukawa Unification

Supersymmetric gauge theories, in higher dimensions compactified in an orbifold, give a natural framework to unify the gauge bosons, Higgs fields and even the matter fields in a single multiplet of the unifying gauge symmetry. The extra dimensions and the supersymmetry are the two key ingredients for such an unification. In this work, we investigate various scenarios for the unification of the three gauge couplings, and the Yukawa couplings in the Minimal Supersymmetric Stand...

We study grand unified models in the five-dimensional space-time where the extra dimension is compactified on $S^1/Z_2$. The spontaneous breaking of unified gauge symmetries is achieved via vacuum expectation values of the extra-dimensional components of gauge fields. We derive one-loop effective potentials for the zero modes of the gauge fields in SU(7), SU(8), SO(10), and $E_6$ models. In each model, the rank of the residual gauge symmetry that respects the boundary conditi...

We study supersymmetric unified models with three fermion generations based on the gauge group $SO(10)$ and require Gauge-Yukawa Unification, i.e., a renormalization group invariant functional relationship among the gauge and Yukawa couplings of the third generation in the symmetric phase. In the case of the minimal model, we find that the predicted values for the top and bottom quark masses are in agreement with the present experimental data for a wide range of supersymmetry...

We perform a general 1-loop analysis by adding extra matter to the SM content, as well as by allowing a non-standard U(1)Y normalization in order to achieve unification. We find numerous solutions with U(1)Y only charged extra matter and unification scale of the order of MU=10^{16} GeV, or with SU(2) charged extra matter with lower MU. We next identify the SM extra matter as originating from the breaking of SO(10) either through the Pati-Salam group SU(4)xSU(2)LxSU(2)R or the...

We examine gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking. We work consistently to two-loop order, and include all weak, messenger and unification-scale threshold corrections. We find that successful unification requires unification-scale threshold corrections that are in conflict with the minimal SU(5) model, but are consistent with the modified missing doublet SU(5) model for small tan beta, and large tan beta with mu>0.

We discuss the possibility of unifying in a simple and economical manner the Yukawa couplings of third generation fermions in a non-supersymmetric SO(10) model with an intermediate symmetry breaking, focusing on two possible patterns with intermediate Pati-Salam and minimal left-right groups. assume a minimal Yukawa sector at high energy, starting with two Higgs bi-doublets at the intermediate scale which then simply reduce to a two Higgs doublet model at the electroweak scal...

We discuss how unification of the gauge, Higgs and (three chiral family) matter superfields can be realized from the compactification of a six dimensional supersymmetric SU(8) gauge theory over the orbifold R^4 x T^2/Z_3. The bulk gauge interaction includes Yukawa interactions to generate masses for quarks and leptons after the electroweak symmetry is broken. The Yukawa matrices in this case turn out to be antisymmetric, and thus not phenomenologically viable. To overcome thi...

We construct a minimal supersymmetric SO(10) grand unified model in 5 dimensions. The extra dimension is compactified on an S^1/(Z_2 x Z_2^\prime) orbifold which has two in-equivalent fixed points. These are flat 4-dimensional Minkowski spaces: the visible and the hidden branes. By orbifolding, the gauge symmetry on the hidden brane is reduced down to the Pati--Salam gauge symmetry SU(4) x SU(2)_L x SU(2)_R. On the visible brane the SO(10) is broken by the ordinary Higgs mech...

We construct concrete supersymmetric grand unified theories based on the Pati-Salam gauge group SU(4)_c x SU(2)_L x SU(2)_R which naturally lead to a moderate violation of "asymptotic" Yukawa unification and thus can allow an acceptable b-quark mass even with universal boundary conditions. We consider the constrained minimal supersymmetric standard model which emerges from one of these theories with a deviation from Yukawa unification which is adequate for mu>0. We show that ...

Inspired by the string landscape and the unified gauge coupling relation in the F-theory Grand Unified Theories (GUTs) and GUTs with suitable high-dimensional operators, we study the canonical gauge coupling unification and Higgs boson mass in the Standard Model (SM) with high-scale supersymmetry breaking. In the SM with GUT-scale supersymmetry breaking, we achieve the gauge coupling unification at about 5.3 x 10^{13} GeV, and the Higgs boson mass is predicted to range from 1...