Related papers: Gauge coupling constant, compositeness and supersy…
We study in two space-time dimensions (d = 2) the relation between N = 2 supersymmetric (SUSY) QED theory and N = 2 nonlinear (NL) SUSY model by linearizing N = 2 NLSUSY generally based upon the fundamental notions of the basic theory. We…
We study the coupling matrix of $\mathcal{N}=2$ $SU(N)$ gauge theories with $2N$ fundamental hypermultiplets in the special vacuum, where a residual $\mathbb{Z}_N$ symmetry restores nontrivial modular structure. Using symmetry and…
We make a detailed study of the unification of gauge couplings in the MSSM with large extra dimensions. We find some scenarios where unification can be achieved (with the strong coupling constant at the Z mass within one standard deviation…
A generic lesson of string theory is that the coupling constants of an effective low energy theory are determined by the vacuum values of a set of fields - the so-called moduli - some of which are stabilized at relatively low masses by…
The prediction of the strong coupling constant in grand unified theories is reviewed, first in the standard model, then in the supersymmetric version. Various corrections are considered. The predictions in both supergravity-induced and…
The apparent unification of gauge couplings around 10^16 GeV is one of the strong arguments in favor of Supersymmetric extensions of the Standard Model (SM). In this contribution two new analyses of the gauge coupling running, the latter…
We discuss explicitly the details and some remarkable physical consequences of the NL/L SUSY relation between N = 2 LSUSY QED and N = 2 NLSUSY in two-dimensional space-time, which may show the potential of the SUSY composite model for the…
We discuss the coupled variations of the gravitational, strong and electroweak coupling constants and the current knowledge of the nuclear equation of state based on heavy ion collision experiments and neutron star mass-radius relationship.…
The apparent unification of gauge couplings around 10^16 GeV is one of the strong arguments in favor of Supersymmetric extensions of the Standard Model (SM). In this contribution a new analysis, using the latest experimental data, is…
The MSSM distinguishes itself from other GUT's by a successful prediction of many unrelated phenomena with a minimum number of parameters. Among them: a) Unification of the couplings constants; b)Unification of the masses; c) Proton decay;…
The unification of gauge coupling constants in the minimal supersymmetric model (MSSM) is unaffected at the one-loop level by the inclusion of additional mass-degenerate SU(5) multiplets. Perturbativity puts an upper limit on the number of…
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…
There are many theories of quantum gravity, depending on asymptotic boundary conditions, and the amount of supersymmetry. The cosmological constant is one of the fundamental parameters that characterize different theories. If it is…
By solving the compositeness condition, under which the Yukawa-type model coincides the NJL type model, we obtain the expressions for the effective coupling constants in terms of the compositeness scale at the next-to-leading order in 1/N.…
The results for the running of the gauge couplings in the MSSM are up-dated by proper inclusion of all low scale effects. They are presented as predictions for the strong coupling constant in the scenario with only two parameters at the GUT…
Supersymmetry implies that the trilinear couplings between gauge bosons and gauginos are equal to all orders in perturbation theory. However if SUSY is broken and some of the superpartners have large SUSY breaking masses then they can…
We consider a quark-lepton symmetry model of unification of the strong and electromagnetic interactions. The model has the gauge group $SU(4)\times U(1)_{Y}$ and the minimal Higgs structure consisting of one complex quartet of scalar…
Causality constrains the gravitational interactions of massive higher spin particles in both AdS and flat spacetime. We explore the extent to which these constraints apply to composite particles, explaining why they do not rule out…
Astrophysical indications that the fine structure constant is time dependent are discussed in the framework of grand unification models. A variation of the electromagnetic coupling constant could either be generated by a corresponding time…
A coupling-constant definition is given based on the compositeness property of some particle states with respect to the elementary states of other particles. It is applied in the context of the vector-spin-1/2-particle interaction vertices…