相关论文: Non-Canonical MSSM, Unification, And New Particles…
We explore the extent to which string theories with higher-level gauge symmetries and non-standard hypercharge normalizations can reconcile the discrepancy between the string unification scale and the GUT scale extrapolated from the Minimal…
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). Considering grand unification scale supersymmetry breaking, we show that gauge…
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…
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…
We show how gauge coupling unification near the Planck scale $M_P\sim 10^{19}$ GeV can be achieved in the framework of supersymmetry, facilitating a full unification of all forces with gravity. Below the conventional GUT scale $M_{GUT}\sim…
We consider gauge unification in nonminimal models with extra spacetime dimensions above the TeV scale. We study the possibility that only a a subset of the supersymmetric standard model gauge and Higgs fields live in the higher dimensional…
We explore in a model independent way the possibility of achieving the non supersymmetric gauge coupling unification within left-right symmetric models, with the minimal particle content at the left-right mass scale which could be as low as…
We present an updated assessment of the viability of t-b-tau Yukawa coupling unification in supersymmetric models. For the superpotential Higgs mass parameter mu>0, we find unification to less than 1% is possible, but only for GUT scale…
Supersymmetric grand unified models based on SO(10) gauge symmetry have many desireable features, including the unification of Yukawa couplings. Using D-term contributions to scalar masses arising from the breakdown of SO(10), Yukawa…
We systematically construct two kinds of models with canonical gauge coupling unification and universal high-scale supersymmetry breaking. In the first we introduce standard vector-like particles while in the second we also include…
Supersymmetric Grand Unification usually provides unification of the bottom quark and the tau lepton Yukawa couplings at the GUT scale. In the CMSSM this can be realised only for a very particular choice of parameters. In this letter we…
Unparticle physics from a hidden conformal sector can alter the evolution of the Standard Model (SM) gauge couplings via TeV scale threshold corrections. We discuss how this may lead to gauge coupling unification at M_{GUT}\approx 2 \times…
We undertake a phenomenological study of SU(5) F-theory GUT models with an additional U(1)_{PQ} symmetry. In such models, breaking SU(5) with hypercharge flux leads to the presence of non-GUT multiplets in the spectrum. We study the effect…
Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at…
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 use a new approach to study string scale gauge coupling unification systematically, allowing both the possibility of non-canonical U(1)_Y normalization and the existence of vector-like particles whose quantum numbers are the same as…
We investigate constraints that the requirements of perturbativity and gauge coupling unification impose on extensions of the Standard Model and of the MSSM. In particular, we discuss the renormalization group running in several SUSY…
We consider $b$-$\tau$ unification in supersymmetric $SU(5)$ grand unified theories (GUTs) with extra matters. The renormalization group runnings of $b$ and $\tau$ Yukawa coupling constants may be significantly affected by the existence of…
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…
Unification of Gauge and Yukawa sectors of GUTs is obtained by searching for renormalization group invariant relations among the couplings of the both sectors which hold beyond the unification scale. This procedure singled out two…