Related papers: Coupling Constant Unification in Extensions of Sta…
We look for minimal extensions of Standard Model with vector like fermions leading to precision unification of gauge couplings. Constraints from proton decay, Higgs stability and perturbativity are considered. The simplest models contain…
We study the effects of additional fields on the unification of gauge couplings in supersymmetric models. We find that the effects are quite constrained by the requirement of SU(5) gauge invariance. In general, we find that any extension of…
We calculate renormalized Higgs boson couplings with gauge bosons and fermions at the one-loop level in the model with an additional isospin singlet real scalar field. These coupling constants can deviate from the predictions in the…
The string landscape suggests that the supersymmetry breaking scale can be high, and then the simplest low energy effective theory is the Standard Model (SM). We show that gauge coupling unification can be achieved at about 10^{16-17} GeV…
I try to assess the weak and strong points of the standard model of electro-magnetic, weak and strong forces, how it can be derived from general relativity by generalizing Riemannian to noncommutative geometry and what post- and predictions…
Unification of the interactions of the Standard Model is possible in its simplest supersymmetric extension. The implications of the $\lambda _t$ fixed-point solution on the top mass and on Higgs phenomenology is discussed. Expected…
Using the current precision electroweak data, we look for the minimal particle content which is necessary to add to the standard model in order to have a complete unification of gauge couplings and gravity at the weakly coupled heterotic…
The question of whether classically conformal modifications of the standard model are consistent with experimental obervations has recently been subject to renewed interest. The method of Gildener and Weinberg provides a natural framework…
I discuss the matching relations for the running renormalizable parameters when the heavy particles (top quark, Higgs scalar, Z and W vector bosons) are simultaneously decoupled from the Standard Model. The complete two-loop order matching…
The progress of Particle Physics is closely linked to the progress in the understanding of the fundamental constants, like the finestructure constant, the mass of the electron or nucleon, or the electroweak mixing angle. The relation…
The Cabibbo Angle Anomaly, an apparent deficit in first-row CKM unitarity, can be addressed by leptophilic Standard Model extensions that generate new contributions to the Fermi constant and affect the determination of the CKM element…
We analyze the implications of the light gluino scenario for the unification of gauge and Yukawa couplings within the minimal supersymmetric standard model. Within this scheme all fermionic supersymmetric particles are naturally light,…
The unification of gauge and top Yukawa couplings is an attractive feature of gauge-Higgs unification models in extra-dimensions. This feature is usually considered difficult to obtain based on simple group theory analyses. We reconsider a…
Gauge coupling unification is studied in the MSSM with non-universal soft supersymmetry breaking terms. If gaugino masses are sufficiently smaller than scalar soft masses and the scalar soft masses have also certain types of…
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…
For strong enough Yukawa coupling the electroweak standard model fermion finds it energetically advantageous to transform itself into a bound state in the hedgehog background of Higgs field in semiclassical approximation. By considering the…
We investigate the properties of a Finite Electroweak (FEW) Theory first proposed in 1991. The theory predicts a running of the electroweak coupling constants and a suppression of tree level amplitudes, ensuring unitarity without a Higgs…
General issues in the renormalization group evolution of fermion masses and mixings is discussed. An effective fixed point in the top quark Yukawa coupling can strongly constrain its value at the electroweak scale. Predictions following…
In the standard model the running quartic coupling becomes negative during its renormalization group flow, which destabilizes the vacuum. We consider U(1) extensions of the standard model, with an extra complex scalar field and a…
We consider the renormalisation group flow of gauge couplings within the so-called exceptional supersymmetric standard model (E$_6$SSM) based on the low energy matter content of 27 dimensional representations of the gauge group $E_6$,…