Testing Gauge-Yukawa-Unified Models By $M_t$

Abstract

Gauge-Yukawa Unification (GYU) relates the gauge and Yukawa couplings, thereby going beyond the usual GUTs, and it is assumed that the GYU in the third fermion generation implies that its Yukawa couplings are of the same order as the unified gauge coupling at the GUT scale. We re-examine carefully the recent observation that the top-bottom mass hierarchy can be explained to a certain extent in supersymmetric GYU models. It is found that there are equiv-top-mass-lines in the boundary conditions of the Yukawa couplings so that two different GYU models on the same line can not be distinguished by the top mass $M_t$ alone. If they are on different lines, they could be distinguished by $M_t$ in principle, provided that the predicted $M_t$'s are well below the infrared value $M_t$ (IR). We find that the ratio $M_t(\mathrm{IR})/\sin \beta$ depends on $\tan \beta$ for large $\tan \beta$ and the lowest value of $M_t(\mathrm{IR})$ is $\sim 188$ GeV. We focus our attention on the existing $SU(5)$ GYU models which are obtained by requiring finiteness and reduction of couplings. They, respectively, predict $M_t=(183+{\delta }^{\mathrm{MSSM}}{M}_t\pm 5)$ GeV and $(181+{\delta }^{\mathrm{MSSM}}{M}_t\pm 3)$ GeV, where ${\delta }^{\mathrm{MSSM}}{M}_t$ stands for the MSSM threshold correction and is $\sim -2$ GeV for the case that all the MSSM superpartners have the same mass $M_{\mathrm{SUSY}}$ with ${\mu }_H/M_{\mathrm{SUSY}}<<1$.

29 pages

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Cited by in corpus (29)

• Renormalisation Invariance and the Soft $\beta$-Functions
• Further all-loop results in softly-broken supersymmetric gauge theories
• Constraints on Finite Soft Supersymmetry Breaking Terms
• Constraints on Finite Soft Supersymmetry-Breaking Terms
• Perturbative Unification of Soft Supersymmetry--Breaking Terms
• Running of Soft Parameters in Extra Space-Time Dimensions
• Soft Scalar-Mass Sum Rule in Gauge-Yukawa Unified Models and Its Superstring Interpretation
• All-order Finiteness in N=1 SYM Theories: Criteria and Applications
• Model Building with Gauge-Yukawa Unification
• Coupling Unifications in Gauge-Higgs Unified Orbifold Models
• Finite Theories and the SUSY Flavor Problem
• Reduction of Couplings and its application in Particle Physics
• Finite Theories after the discovery of a Higgs-like boson at the LHC
• Finite Unified Theories and the Higgs boson
• $N=1$ trinification from dimensional reduction of $N=1$, $10D$ $E_8$ over $SU(3)/U(1)\times U(1)\times Z_3$ and its phenomenological consequences
• The LHC Higgs Boson Discovery: Implications for Finite Unified Theories
• Fermion mass hierarchy and non-hierarchical mass ratios in SU(5) x U(1)_F
• Finite Theories Before and After the Discovery of a Higgs Boson at the LHC
• Dualities in all order finite N=1 gauge theories
• Sum rules in the superpartner spectrum of the minimal supersymmetric standard model
• Yukawa Unification in Moduli-dominant SUSY Breaking
• Reduction of the Parameters in MSSM
• Updates and New Results in Models with Reduced Couplings
• Probing Unified Theories with Reduced Couplings at Future Hadron Colliders
• Unified Gauge Theories and Reduction of Couplings: from Finiteness to Fuzzy Extra Dimensions
• Extra dimensions prefer large $\tan \beta$
• Coupling Reduction and the Higgs Mass
• Reduction of Couplings and Finiteness in Realistic Supersymmetric GUTs
• An extension of the standard model with a single coupling parameter