Related papers: A Fourth Chiral Generation And Susy Breaking
Motivated by the coupling unification problem, we propose a novel extension of the Minimal Supersymmetric Standard Model. One of the predictions of this extension is existence of new states neutral under SU(3)_c X SU(2)_w but charged under…
Utilizing the idea of extra large dimensions, it has been suggested that the gauge and gravity couplings unification can happen at a scale as low as 1 TeV. In this paper, we explore this phenomenological possibility within string theory. In…
We consider states in the adjoint representation of the Standard Model gauge group as messengers for mediation of supersymmetry (SUSY) breaking. These new messengers can shift the gauge coupling unification to the string scale at…
We investigate the effects of Yukawa couplings on the phenomenological predictions for a class of supersymmetric models which allows for the presence of complete SU(5) multiplets in addition to the Minimal Supersymmetric Standard Model…
We start a systematic investigation of the possibility to have supersymmetry (SUSY) to be an asymptotic state of the gauge theory in the high energy (UV) limit, due to the renormalization group running of coupling constants of the theory.…
Gauge-Yukawa Unification (GYU) relates the gauge and Yukawa couplings, thereby going beyond the usual GUTs, and it is assumed that the GYU in the third fermion generation implies that its Yukawa couplings are of the same order as the…
We calculate the tree-level electroweak precision constraints on a wide class of little Higgs models including: variations of the Littlest Higgs SU(5)/SO(5), SU(6)/Sp(6), and SU(4)^4/SU(3)^4. By performing a global fit to the precision data…
A realistic SU(3)_C x SU(3)_W unified theory is constructed with a TeV sized extra dimension compactified on the orbifold S_1/Z_2, leaving only the standard model gauge group SU(3)_C x SU(2)_L x U(1)_Y unbroken in the low energy 4D theory.…
Unified theories based on an extended left-right symmetric group, $SU(4) \times SU(2)^4$, are constructed in five dimensions. The compactification scale is assumed to be only a loop factor above the weak scale, so that the weak mixing angle…
In simple SO(10) SUSY GUTs the top, bottom and tau Yukawa couplings unify at the GUT scale. A naive renormalization group analysis, neglecting weak scale threshold corrections, leads to moderate agreement with the low energy data. However…
We consider the maximal U(3) horizontal scheme as a handle on fermion masses and mixings. In particular, we attempt to explain the large top Yukawa coupling and the masses and mixing in the two heaviest generations. A simple model is…
I discuss the properties of the minimal supersymmetric extension of the standard model, in the case in which there is a dynamical breakdown of the electroweak symmetry induced by the formation of condensates of the third generation of…
The conventional method using low energy theorems [3] does not seem to lead to an explicit unitarity limit in the scattering processes of longitudinally polarized gauge bosons for the high energy case in the extra U(1) superstring inspired…
In the two Higgs doublet model, perturbativity breaks down below the Planck scale: For top mass values 170-180 GeV, the Yukawa coupling reaches the pole below 1000 TeV, if the ratio of vev's v_u/v_d is below 1. We discuss top condensate…
The requirement of t-b-\tau Yukawa coupling unification is common in simple grand unified models based on the gauge group SO(10), and it also places a severe constraint on the expected spectrum of superpartners. For Yukawa-unified models…
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 consider electroweak symmetry breaking in supersymmetric models with an extra non-anomalous U(1)' gauge symmetry and an extra standard-model singlet scalar S. For appropriate charges the U(1)' forbids an elementary mu term, but an…
We study perturbative unitarity constraints on generic Yukawa interactions where the involved fields have arbitrary quantum numbers under an $\prod_i SU(N_i) \otimes U(1)$ group. We derive compact expressions for the bounds on the Yukawa…
I analyze the predictions for the strong gauge coupling, $\alpha_3(M_Z) $, and the top quark and light Higgs masses in the framework of gauge and bottom-tau Yukawa coupling unification in the minimal supersymmetric standard model. These…
We present new upper limits on the light Higgs boson mass mh in supersymmetric models. We consider two gravity-mediated models (with and without universal scalar masses) and two gauge-mediated models (with a 5+5 or 10+10 messenger sector).…