Related papers: Quark and lepton masses at the GUT scale including…
We show that the observed structure of quark and lepton masses and mixing angles can arise entirely geometrically from superstring constructions, at the renormalizable level. The model we consider is a $Z_3$ orbifold compactification of…
In N = 1 super Yang-Mills theories, under certain conditions satisfied by the spectrum and the Yukawa couplings, the beta functions will vanish to all orders in perturbation theory. We address the generation of realistic quark mixing angles…
Threshold corrections to the bottom quark mass are often estimated under the approximation that tan$\beta$ enhanced contributions are the most dominant. In this work we revisit this common approximation made to the estimation of the…
Local supersymmetry (SUSY) provides an attractive framework for the incorporation of gravity and unification of gauge interactions within Grand Unified Theories (GUTs). Its breakdown can lead to a variety of models with softly broken SUSY…
We study one loop supersymmetric corrections to precision observables. Adding LEP2 e ebar --> f fbar cross sections to the data-set removes previous hints for SUSY and the resulting constraints are in some cases stronger than direct bounds…
Motivated by the recent measurements of the B_s-\bar{B}_s mass difference from the D0 and CDF collaborations, we probe new physics effects in the B_q-\bar{B}_q mixing within the context of the supersymmetric grand unified model (SUSY GUT).…
An exploratory numerical study of the influence of heavy fermion doublets on the mass of the Higgs boson is performed in the decoupling limit of a chiral $\rm SU(2)_L \otimes SU(2)_R$ symmetric Yukawa model with mirror fermions. The…
We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. In many cases, a…
An analysis is made on bottom-tau Yukawa unification in supersymmetric (SUSY) SU(5) grand unified theory (GUT) in the framework of minimal supergravity, in which the parameter space is restricted by some experimental constraints including…
I examine the possibility that the third generation fermion masses are determined by an exact fixed point of the minimal supersymmetric SU(5) model. When one-loop supersymmetric thresholds are included, this unified fixed point successfully…
Supersymmetric hadrons of the type $\tg\tg$, $\tg g$ and $\tg q\bar q$ could exist depending on the masses of the gluino and the squarks being in an appropriate range of values. We find the energy levels of $\tg g$ and $\tg q\bar q$ bound…
Going beyond the theta function approximation we discuss supersymmetric unification of gauge couplings with exact decoupling of light and heavy particles at energy scales below their masses. We find that the Minimal SUSY model is strongly…
Martin has proposed a scenario dubbed ``compressed supersymmetry'' (SUSY) where the MSSM is the effective field theory between energy scales M_{\rm weak} and M_{\rm GUT}, but with the GUT scale SU(3) gaugino mass M_3<< M_1 or M_2. As a…
We present a new geometric approach to the flavour decomposition of an arbitrary soft supersymmetry-breaking sector in the MSSM. Our approach is based on the geometry that results from the quark and lepton Yukawa couplings, and enables us…
We discuss some recent developments in SUSY Grand Unified Theories based on the gauge group SO(10). Considering renormalisable Yukawa couplings, we present ways to accommodate quark and lepton masses and and mixings.
Effects of electroweak phase transition (EWPT) in balance between baryon excess and the excess of stable quarks of new generation is studied. With the conservation of SU(2) symmetry and other quantum numbers, it makes possible sphaleron…
In a class of F-theory SU(5) GUTs the low energy chiral mass spectrum is obtained from rank one fermion mass textures with a hierarchical structure organised by U(1) symmetries embedded in the exceptional E_8 group. In these theories chiral…
On the basis of the so-called supersymmetric yukawaon model, it is investigated what form of the superpotential W can lead to the observed charged lepton mass spectrum. A simple form of W can speculate reasonable values of K(\mu)=(m_e…
We study the so-called new minimal supersymmetric SO(10) GUT(NMSGUT) where explicit spontaneous symmetry breaking allows determination of superheavy spectrum and thus threshold corrections to the effective MSSM couplings. This provides a…
Predictions for the angular distribution of massive quarks and leptons are presented, including QCD and QED corrections. Recent results for the fermionic part of the two-loop corrections to the electromagnetic form factors are combined with…