Related papers: Calculating Fermion masses in Superstring Derived …
Higgs production from gluon fusion is sensitive to the properties of heavy colored fermions and to the Yukawa couplings, (Y_F M_F)/v, of these particles to the Higgs boson. We compute the two--loop, ${\cal O}((Y_F M_F)^3/v^3)$ contributions…
While the properties of the observed Higgs boson agree with the Standard Model predictions, the hierarchy of fermion masses lacks an explanation within the model. In this work, we propose a fresh approach to this problem, involving a…
We study the implications for bounds on the top quark pole mass m_t in models with low scale supersymmetry following the discovery of the Standard Model-like Higgs boson. In the minimal supersymmetric standard model, we find that m_t >= 164…
We show that, in frameworks of the economical 3-3-1 model, all fermions get masses. At the tree level, one up-quark and two down-quarks are massless, but the one-loop corrections give all quarks the consistent masses. This conclusion is in…
Hypotheses of the universal seesaw mechanism and the {\it universal strength for Yukawa couplings} are applied to explain one possible origin of quasi-democratic mass matrices of a special type in a left-right symmetric model with the gauge…
A predictive framework for fermion masses and mixing is given by the supersymmetric SO(10) model with one 10, one bar126, one 126 and one 210 Higgs representations, and type II seesaw dominating the neutrino mass matrix. We investigate the…
We propose a simple $SU(5)$ model that connects the neutrino mass generation mechanism to the observed disparity between the masses of charged leptons and down-type quarks. The model is built out of $5$-, $10$-, $15$-, $24$-, and…
We investigate the Higgs-Yukawa system with Majorana masses of a fermion within asymptotically safe quantum gravity. Using the functional renormalization group method we derive the beta functions of the Majorana masses and the Yukawa…
We propose a supersymmetric extension of the anomaly-free and three families nonuniversal $U(1)$ model, with the inclusion of four Higgs doublets and four Higgs singlets. The quark sector is extended by adding three exotic quark singlets,…
It is shown that fine-tuning of the Higgs parameters stronger than a few % is required at the best in the models with gauge mediated supersymmetry breaking. With the aim of solving this problem, we consider a new type of models in which the…
We study a non-supersymmetric SO(10) Grand Unification Theory with a very high energy intermediate symmetry breaking scale in which not only gauge but also Yukawa coupling unification are enforced via suitable threshold corrections and…
The multiple point criticality principle is applied to the pure Standard Model (SM), with a desert up to the Planck scale. We are thereby led to impose the constraint that the effective Higgs potential should have two degenerate minima, one…
Measurement of the top-Yukawa coupling is important to understand the fermion mass generation mechanism and dynamics of electroweak symmetry breaking. We discuss the top quark anomalous couplings which can be described by higher dimensional…
It is well known that the supersymmetric finite threshold effects can induce substantial corrections to the Standard Model fermion masses. This opens an alternative possibility to correct the problematic mass ratios of the lighter…
In this talk, I present a new framework to understand the long-standing fermion mass hierarchy puzzle. We extend the Standard Model gauge symmetry by an extra local U(1)_S symmetry, broken spontaneously at the electroweak scale. All the SM…
If the scale dependence of a Yukawa matrix is assumed to be determined entirely by the dominant 33-element, then the renormalization group equations can be expressed in terms of two separate equations: a differential equation for the…
We analyse the structure of Yukawa couplings in local SU(5) F-theory models with $E_8$ enhancement. In this setting the $E_8$ symmetry is broken down to SU(5) by a 7-brane configuration described by T-branes, all the Yukawa couplings are…
Extra vector-like matter with both electroweak-singlet masses and large Yukawa couplings can significantly raise the lightest Higgs boson mass in supersymmetry through radiative corrections. I consider models of this type that involve a…
Using the Yukawa couplings of the minimal supersymmetric SU(5) model, the rates for $\mu \to e\gamma$, $\mu \to e$ conversion and $\tau \to \mu \gamma$ are computed. For a selectron mass of 100 GeV, and without exploring the full parameter…
We investigate the viability of predictive schemes for quark-lepton Yukawa ratios and nucleon decay in non-supersymmetric SU(5) Grand Unified Theories (GUTs) where neutrino masses are generated by a type II seesaw mechanism. The scalar…