Related papers: Grand Unification and B & L Conservation
We consider five dimensional (5D) supersymmetric SO(10) compactified on the orbifold $S^1/(Z_2\times Z_2')$ such that the SO(10) gauge symmetry is broken on both fixed points (branes), and the residual gauge symmetry is $SU(3)_c\times…
The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection rules apply to baryon number violating…
We point out that if there is a gauged $B-3L_\tau$ symmetry at low energy, it can prevent fast proton decay. This may help building models with theories with extra dimensions at the TeV scale. For purpose of illustration we present an…
We discuss proton decay in a recently proposed model of supersymmetric hybrid inflation based on the gauge symmetry $SU(4)_c \times SU(2)_L \times SU(2)_R$. A $U(1)\, R$ symmetry plays an essential role in realizing inflation as well as in…
We study gravity mediated supersymmetry breaking in ${\cal F}$-SU(5) and its low-energy supersymmetric phenomenology. The gaugino masses are not unified at the traditional grand unification scale, but we nonetheless have the same one-loop…
We review the main constraints on the parameter space of the minimal renormalizable supersymmetric SU(5) grand unified theory. They consist of the Higgs mass, proton decay, electroweak symmetry breaking and fermion masses. Superpartner…
The issue of gauge unification in the (non-supersymmetric) Standard Model is reinvestigated. It is found that with just an additional fourth generation of non-sequential and long-lived quarks and leptons, SU(3)xSU(2)xU(1) gauge couplings…
Gauge-Higgs grand unification is formulated. By extending $SO(5) \times U(1)_X$ gauge-Higgs electroweak unification, strong interactions are incorporated in $SO(11)$ gauge-Higgs unification in the Randall-Sundrum warped space. Quarks and…
Grand Unified Theories (GUT) offer an elegant and unified description of electromagnetic, weak and strong interactions at high energy scales. A phenomenological and exciting possibility to grasp GUT is to search for TeV scale observables…
In the past year, a new non-supersymmetric framework for electroweak symmetry breaking (with or without Higgs) involving SU(2)_L * SU(2)_R * U(1)_{B-L} in higher dimensional warped geometry has been suggested. In this work, we embed this…
We investigate the possibility to realize the unification of the Standard Model gauge interactions at the low scale in four dimensions. We find that the fields needed to define a minimal theory where baryon and lepton numbers are local…
Models of supersymmetric grand unified theories based on SU(5)_GUT \times U(N)_H gauge group (N = 2,3) have a symmetry that guarantees light Higgs doublets and absence of dimension-five proton decay operators. We analysed the proton decay…
An analysis of the $b \rightarrow s\gamma$ is given in supergravity grand unification using the framework of the radiative breaking of the electro-weak symmetry under three separate sets of constraints:1) neutralino relic density does not…
Extensions of the standard model with low-energy supersymmetry generically allow baryon- and lepton-number violating operators of dimension four and five, yielding rapid proton decay. The dimension-four operators are usually forbidden by…
$SO(11)$ gauge-Higgs grand unification in the Randall-Sundrum warped space is proposed. Orbifold boundary conditions and one brane scalar field reduce $SO(11)$ to the standard model symmetry, which is further broken to $SU(3)_C \times…
We consider proton stability based on E_6 inspired extra U(1) model with S_4 x Z_2 flavor symmetry. In this model, a long life time of proton is realized by the flavor symmetry in several ways. We classify the suppression mechanisms of…
A constraint on masses of superheavy gauge and Higgs multiplets at the grand unification (GUT) scale is obtained from the gauge coupling unification in the case of high-scale supersymmetry. We found that all of the particles may lie around…
We construct a simple model of an SU(5) GUT with gauge mediated supersymmetry breaking from a metastable vacuum of a hidden sector. All mass parameters and hierarchies of our model are generated dynamically from retrofitting. This includes…
Frozen SUSY is the maximally suppressed Supersymmetric SU(5) Grand Unified Theory coupled to Supergravity. In Frozen SUSY, there is only one extra particle in addition to those that appear in the usual non-supersymmetric SU(5) Grand Unified…
The possible role of supersymmetry in our understanding of big bang baryogenesis and cosmological dark matter is explored. The discussion will be limited to the out-of equilibrium decay scenario in SUSY GUTs, the decay of scalar…