Related papers: Quark and lepton masses at the GUT scale including…
In this paper we compute the $\mathcal{O}(\alpha_s \alpha_t)$ threshold corrections to the running strong coupling constant, the top-Yukawa coupling and the top-quark mass within the MSSM. These parameters present a non-decoupling behaviour…
We consider an extension of the Georgi-Glashow SU(5) GUT model by a 45-dimensional scalar and a 24-dimensional fermionic representation, where the latter leads to the generation of the observed light neutrino masses via a combination of a…
Including contributions of scale-dependent vacuum expectation values, we derive new analytic formulas and obtain substantially different numerical predictions for the running masses of quarks and charged-leptons at higher scales in the SM,…
Integration of superpartners out of the spectrum induces potentially large contributions to Yukawa couplings. These corrections, the supersymmetric threshold corrections, therefore influence the CKM matrix prediction in a non-trivial way.…
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…
It is well-known that the $SU(5)$ grand unified theory, with the standard model quarks and leptons unified in $\overline{5}$ and $10$ and the electroweak Higgs doublet residing in $5$ dimensional representations, leads to relation,…
We evaluate the supersymmetric QCD corrections to single top quark production via $q \bar q'\to t \bar b$ at the Fermilab Tevatron in the minimal supersymmetric model. We find that within the allowed range of squark and gluino masses the…
A brief review is given of recent analyses of the effects of CP phases on the supersymmetric QCD and supersymmetric electroweak contibutions to the $b$ and $t$ quark masses and to the $\tau$ lepton mass in SUGRA models. The effects of CP…
The paper addresses the effects of the variations of the SUSY breaking scale $m_s$ in the range (2-14) TeV on the three neutrino masses and mixings, in running the renormalization group equations (RGEs) for different input values of high…
The scaling behavior of gauge couplings and fermion Yukawa couplings in the minimal supersymmetric model is discussed. The relevance of the top quark Yukawa coupling fixed point in establishing the top quark mass is described. The evolution…
Supersymmetric SO(10) Grand Unified Theories with Yukawa unification represent an appealing possibility for physics beyond the Standard Model. However Yukawa unification is made difficult by large threshold corrections to the bottom mass.…
Fermion masses and mixing angles are studied in an SUSY $SO(10)\times \Delta (48)\times U(1)$ model with small $\tan\beta$. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully…
We investigate three different possibilities for improving the fermion mass relations that arise in grand unified theories (GUTs). Each scenario relies on supersymmetric loop effects alone, without modifying the naive Yukawa unification.…
Supersymmetric Grand Unification usually provides unification of the bottom quark and the tau lepton Yukawa couplings at the GUT scale. In the CMSSM this can be realised only for a very particular choice of parameters. In this letter we…
We calculate quark and lepton masses and quark mixing angles in the framework of a supersymmetric SU(4)$\otimes$SU(2)$_L\otimes$SU(2)$_R$ model where the gauge group is broken at 10$^{16}$ GeV. The model predicts third family top-bottom-tau…
The effective bottom Yukawa couplings are analyzed for the minimal supersymmetric extension of the Standard Model at two-loop accuracy within SUSY-QCD. They include the resummation of the dominant corrections for large values of tg(beta).…
A new ansatz of democratic lepton mixing is proposed at the GUT scale and the radiative corrections to its phenomenological consequences are calculated at the electroweak scale. We demonstrate that it is possible to obtain the…
The unification of gauge and Yukawa couplings within the minimal supersymmetric standard model is studied at the two loop level. We derive an expression for the effective scale, $T_{SUSY}$, which characterizes the supersymmetric particle…
In the minimal supersymmetric extension of the Standard Model (MSSM), fermion masses and Yukawa couplings receive radiative corrections at one loop from diagrams involving the supersymmetric particles. The corrections to the relation…
I discuss the calculation of the heavy generation masses in the superstring derived standard-like models. The top quark Yukawa coupling is obtained from a cubic level mass term while the bottom quark and tau lepton mass terms are obtained…