Related papers: A Fresh Look at Gauge Coupling Unification
We study the finely tuned SSM, recently proposed by Arkani-Hamed and Dimopoulos, at the one loop level. The runnings of the four gaugino Yukawa couplings, the mu term, the gaugino masses, and the Higgs quartic coupling are computed. The…
Perturbative supersymmetric gauge coupling unification is possible in six theories where complete SU(5) TeV-scale multiplets of vector matter account for the size of the reported $750~{\rm GeV}$ diphoton resonance, interpreted as a singlet…
With minimal field content and for an interesting range of the supersymmetric Higgs mixing parameter, 0.5 < tan^2 \beta < 2, the superpartner mass scale, \tilde{m}, is found to be at the intermediate scale, ~ 10^{10 \pm 1} GeV, near where…
We study non-universal corrections to the gauge couplings due to higher dimensional operators in supersymmetric SU(5) grand unified theories. The corrections are, in general, parametrized by three components originating from {\bf 24}, {\bf…
We embed a theory with Zprime gauge boson (related to extra U(1) gauge group) into a supersymmetric GUT theory based on SO(10). Two possible sequences of SO(10) breaking via VEVs of appropriate Higgs fields are considered. Gauge coupling…
Using two-loop renormalization group equations implementing the decoupling of heavy scalars, Effective SUSY scenarios are studied in the limit in which there is a single low energy Higgs field. Gauge coupling unification is shown to hold…
We study gauge coupling unification and various phenomenological issues, such as baryon number conservation, the $\mu $ problem and neutrino anomalies, within SUSY 5D orbifold models. The 5D MSSM on an $S^{(1)}/Z_2$ orbifold with 'minimal'…
We show that gauge coupling unification is realized with a greater accuracy in the presence of a massless hidden photon which has a large kinetic mixing with hypercharge. We solve the renormalization group equations at two-loop level and…
We discuss the unification of gauge couplings within the framework of a wide class of realistic free-fermionic string models which have appeared in the literature, including the flipped SU(5), SO(6)xSO(4), and various SU(3)xSU(2)xU(1)…
We consider the scenario where all the couplings in the theory are strong at the cut-off scale, in the context of higher dimensional grand unified field theories where the unified gauge symmetry is broken by an orbifold compactification. In…
We study the gauge coupling unification with extra dimensions. We take into account corrections due to the higher dimensional operators. We show the prediction of $\alpha_3(M_Z)$ is sensitive to such corrections, even if…
Standard (level one) heterotic string models with standard model gauge group predict the unification of $SU(3)$ and $SU(2)$ gauge couplings whereas the $U(1)$ factor is unified modulo an unknown normalization factor $k_1$. On the other hand…
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;…
An introduction to the most important concepts in the subject of supersymmetric unified theories is presented. The emphasis is on the practical aspects leading to state-of-the-art calculations in this renascent subject. The topics covered…
We recalculate the two-loop beta functions for three gauge couplings taking into account all low energy threshold corrections in split supersymmetry (split-SUSY) which assumes a very high scalar mass scale M_S. We find that, in split-SUSY…
Extrapolating the coupling strengths to very high energies, one finds that they do not converge to a single coupling constant, as expected in the simplest gauge theory of Grand Unification, the SU(5) theory. We find that the coupling…
The logarithmic running of the gauge couplings alpha_1, alpha_2 and alpha_3, indicates that they may unify at some scale M_GUT ~ 10^16. This is often taken to imply that the standard model gauge group is embedded into some larger simple…
In the present paper we demonstrate the possibility of the [SUSY(5)]^3 SUSY unification at the energy scale $\mu_{GUT}\approx 10^{18.3} GeV$ with the value of GUT inverse finestructure constant $\alpha_{GUT}^{-1}\approx 34.4$, which is very…
The string theory predicts the unification of the gauge couplings and gravity. The minimal supersymmetric Standard Model, however, gives the unification scale $\sim 2\times 10^{16}$ GeV which is significantly smaller than the string scale…
We report on a preferred region of supersymmetric parameter space by t, b, tau Yukawa unification. We find a narrow region survives for mu > 0 (suggested by b --> s gamma and the anomalous magnetic moment of the muon) with A_0 \sim - 2…