Related papers: Roadmap of left-right models based on GUTs
Dimension-5 corrections to the gauge kinetic term of Grand Unified Theories (GUTs) may capture effects of quantum gravity or string compactification. Such operators modify the usual gauge coupling unification prediction in a calculable…
We consider a minimal renormalizable non-supersymmetric $E_6$ Grand Unified Theory using fundamental representation $27$ for fermions and scalars. The scalar with adjoint representation ${78}$ is also taken for direct breaking of $E_{6}$ to…
Going beyond the theta function approximation we discuss supersymmetric unification of gauge couplings with exact decoupling of light and heavy particles at energy scales below their masses. We find that the Minimal SUSY model is strongly…
The nature of R-parity violating interactions in two classes of string inspired supersymmetric grand unified theories (SISUSY GUT), based on the gauge groups $SO(10)$ (and its subgroup $SU(2)_L\times SU(2)_R\times SU(4)_c\equiv G_{224}$) as…
The success of SU(5)-like gauge coupling unification boundary conditions $g_3^2=g_2^2=5/3 g_1^2$ has biased most attempts to embed the SM interactions into a unified structure. After discussing the limitations of the orthodox approach, we…
We examine a superpotential for an SO(10) GUT and show that if the parameters of the superpotential are in a certain region, the SO(10) GUT has an intermediate symmetry ${\rm SU(2)}_L \otimes {\rm SU(2)}_R \otimes {\rm SU(3)}_C \otimes {\rm…
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…
In this talk, we introduce a new scenario of grand unified theory (GUT) with anomalous $U(1)_A$ gauge symmetry, which can explain doublet-triplet splitting, quark and lepton masses and mixing angles. In neutrino sector, the scenario…
These lectures begin with a brief introduction to the minimal supersymmetric standard model (MSSM) and the various mechanisms for hidden sector supersymmetry breaking and go on to provide a pedagogical discussion of the various kinds of…
We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the…
We recapitulate the primary sources of theoretical uncertainties in proton lifetime estimates in renormalizable, four-dimensional and non-supersymmetric grand unifications that represent the most conservative framework in which this…
In a recent paper, we proposed a new class of supersymmetric SO(10) models for neutrino masses where the TeV scale electroweak symmetry is SU(2)_L\times SU(2)_R\times U(1)_{B-L} making the associated gauge bosons W_R and Z' accessible at…
Generic SO(10) GUT models suffer from the problem that Planck scale induced non-renormalizable proton decay operators require extreme suppression of their couplings to be compatible with present experimental upper limits. One way to resolve…
Unlike minimal SU(5), SO(10) provides a straightforward path towards gauge coupling unification by modifying the renormalization group evolution of the gauge couplings above some intermediate scale which may also be related to the seesaw…
We study the impact of multiple vector-like fermions in SU(5) grand unified theory (GUT). Threshold effects from extra fermions allow the observed gauge couplings to be consistently matched to a single unified gauge coupling, and typically…
Proton decay is a smoking gun signature of Grand Unified Theories (GUTs). Searches by Super-Kamiokande have resulted in stringent limits on the GUT symmetry breaking scale. The large-scale multipurpose neutrino experiments DUNE,…
We briefly review the issues of proton decay and fermion masses and mixings in minimal supersymmetric grand unified theories. We argue that minimal SU(5), although tightly constrained by proton decay data, is still not ruled out. However,…
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'…
The idea of grand unification in a minimal supersymmetric SU(5)xSU(5) framework is revisited. It is shown that the unification of gauge couplings into a unique coupling constant can be achieved at a high-energy scale compatible with proton…
Nucleon lifetimes for various decay modes via dimension 6 operators are calculated in the anomalous $U(1)_A$ GUT scenario, in which the unification scale $\Lambda_u$ becomes smaller than the usual supersymmetric (SUSY) unification scale…