Related papers: Supergravity Grand Unification, Proton Decay and C…
Maximally supersymmetric SO(10) and SU(6) unified theories are constructed on the orbifold T^2/(Z_2 x Z'_2), with one length scale R_5 taken much larger than the other, R_6. The effective theory below 1/R_6 is found to be the highly…
We investigate a simple realistic grand unified theory based on the $SU(5)$ gauge symmetry which predicts an upper bound on the proton decay lifetime for the channels $p \to K^+ \bar{\nu}$ and $p \to \pi^+ \bar{\nu}$, i.e. $\tau (p \to K^+…
We propose a predictive $SO(10)$ Grand Unified Theory (GUT) framework for cosmic inflation in the Palatini $\mathcal{R}^2$ formulation of gravity. In this model, a GUT Higgs field both drives inflation and induces intermediate-scale…
Gauge coupling unification in the Minimal Supersymmetric Standard Model (MSSM) strongly suggests the existence of a Grand Unified Theory (GUT), which could be probed by the observation of proton decay. Proton lifetime in the p \to (e+|mu+)…
SU(5) $\otimes$ SU(5) provides a minimal grand unification scheme for fermions and gauge forces if there are vector-like quarks and leptons in nature. We explore the gauge coupling unification in a non-supersymmetric model of this type, and…
A survey is given of supersymmetry and supergravity and their phenomenology. Some of the topics discussed are the basic ideas of global supersymmetry, the minimal supersymmetric Standard Model (MSSM) and its phenomenology, the basic ideas…
We consider proton decay and $g_\mu - 2$ in flipped SU(5) GUT models. We first study scenarios in which the soft supersymmetry-breaking parameters are constrained to be universal at some high scale $M_{in}$ above the standard GUT scale…
We discuss the proton lifetime in pure gravity mediation models with non-universal Higgs soft masses. Pure gravity mediation offers a simple framework for studying SU(5) grand unified theories with a split supersymmetry like spectra. We…
It has been shown recently that the problem of rapid proton decay induced by dimension five operators arising from the exchange of colored Higgsinos can be simply avoided in grand unified models where a fifth spatial dimension is…
We provide detailed estimates of the proton lifetime in the context of simple supersymmetric SU(5) grand unified models with an extra compact spatial dimension, described by the orbifold S/(Z_2 x Z_2') and by a large compactification scale…
The current measurement of the Higgs mass, the ubiquitous nature of loop-suppressed gaugino masses in gravity-mediated supersymmetry breaking, relic dark matter density from $\sim$ TeV mass gauginos, together with the success of…
Higher dimensional grand unified theories, with gauge symmetry breaking by orbifold compactification, possess SU(5) breaking at fixed points, and do not automatically lead to tree-level gauge coupling unification. A new framework is…
4D Higgs field is identified with the extra-dimensional component of gauge potentials in the gauge-Higgs unification scenario. $SO(5) \times U(1)$ gauge-Higgs EW unification in the Randall-Sundrum warped space is successful at low energies.…
The minimal supersymmetric $SU(5)$ grand unified theory (GUT) provides a highly compelling framework for physics beyond the Standard Model (SM). However, it suffers from a severe phenomenological challenge: rapid proton decay mediated by…
The status of top-bottom-tau Yukawa coupling unification in supersymmetric SO(10) models is reviewed with a particular emphasis on the implications of the Higgs boson mass in the vicinity of 125 GeV, as suggested by the LHC Higgs data. In…
We derive in detail a condition on the Higgs mass parameters that is necessary for the recently proposed ``split supersymmetry'' (split SUSY) scenario to provide a realistic magnitude of $\tan \beta$. The nature of this condition can be…
In a model of supersymmetric SU(5) Grand Unification with a spatial dimension described by the orbifold $S^1/(Z_2 \times Z_2')$, proton decay is naturally suppressed at all orders. This is achieved by a suitable implementation of the…
Gauge coupling unification in the Supersymmetric Standard Models strongly implies the Grand Unified Theories (GUTs). With the grand desert hypothesis, we show that the supersymmetric GUTs can be probed at the future proton-proton (pp)…
Supersymmetric grand unified models based on the gauge group SU(5) often require in addition to gauge coupling unification, the unification of b-quark and $\tau$-lepton Yukawa couplings. We examine SU(5) SUSY GUT parameter space under the…
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…