Related papers: Observable Proton Decay in Flipped SU(5)
We study a ${U(1)}_R$ symmetric extenstion of supersymmetric standard model with supersymmetry breaking in the visible as well as hidden sectors. Specifically we study ${U(1)}_R$ breaking effects parametrized by the gravitino mass. A…
We consider the minimal supersymmetric SO(10) model, where only one {\bf 10} and one $\bar{\bf 126}$ Higgs multiplets have Yukawa couplings with matter multiplets. This model has the high predictive power for the Yukawa coupling matrices…
We make a detailed analysis of gauge coupling unification in supersymmetry. When the Standard Model gauge group is embedded in a Grand Unified Theory, new particles often appear below the GUT scale in order to predict the right…
Dimension-five operators for nucleon decays are suppressed in the modified missing doublet (MMD) model in the supersymmetric SU(5) grand unification. We show that nonrenormalizable interactions decrease the unification scale in the MMD…
We study a supersymmetric SU(5) model with the extra Higgs multiplets of 45+\bar 45. The unification of the gauge couplings, the fermion masses and the proton lifetime are discussed in details. The dimension-five operators mediated by…
A mechanism for the enhancement for proton lifetime in supersymmetric/supergravity (SUSY/SUGRA) grand unified theories (GUTs) and in string theory models is discussed where Higgsino mediated proton decay arising from color triplets…
We realize smooth hybrid inflation in the framework of supersymmetric $SU(5) \times U(1)_{\chi}\subset SO(10)$ model which provides a natural solution to the monopole problem appearing in the spontaneous symmetry breaking of $SU(5)$. The…
We propose a mechanism to suppress proton decay induced by dimension-5 operators in a supersymmetric SO(10) model. Proton lifetime is directly connected with the intermediate vacuum expectation value which is responsible for the seesaw…
We present a realistic supersymmetric SU(5) model combined with a non-anomalous U(1)_F symmetry. We find a set of U(1)_F charges which automatically lead to the realistic mass hierarchy and mixing patterns for quarks, leptons and neutrinos.…
It is shown that in realistic SUSY GUT models of quark and lepton masses both the proton decay rate and branching ratios differ in general from those predicted in the minimal $SU(5)$ supersymmetric model. The observation of proton decay,…
It is widely believed that minimal supersymmetric SU(5) GUTs have been excluded by the SuperKamiokande bound for the proton decay rate. In the minimal model, however, the theoretical prediction assumes unification of Yukawa couplings,…
The explanation of various observed phenomena such as large angle neutrino oscillations, hierarchies of charged fermion masses and CKM mixings, and apparent baryon number conservation may have a common origin. We show how this could occur…
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 propose a $SU(5) \times U(1)_X \times U(1)_{PQ}$ model, where $U(1)_X$ is the generalization of the $B-L$ (baryon minus lepton number) gauge symmetry and $U(1)_{PQ}$ is the global Peccei-Quinn (PQ) symmetry. There are four fermions…
Product group unification is an attractive alternative to simple grand unification. It solves the infamous doublet-triplet splitting problem and the dimension-5 proton decay problems without introducing any fine-tuning. Furthermore, the…
In supersymmetry, there are gauge invariant dimension 5 proton decay operators which must be suppressed by a mass scale much larger than the Planck mass. It is natural to expect that this suppression should be explained by a mechanism that…
We make a detailed analysis on the nucleon decay in the minimal supersymmetric $SU(5)$ grand unified model. We find that a requirement of the unification of three gauge coupling constants leads to a constraint on a mass $M_{H_C}$ of…
The proton decay modes $p\to K^0 e^+$ and $p\to K^0 \mu^+$ may be visible in certain supersymmetric theories, and if seen would provide evidence for new flavor physics at extremely short distances. These decay modes can arise from the…
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…
We present the results of an extensive exploration of the five-dimensional parameter space of the minimal $SU(5)$ supergravity model, including the constraints of a long enough proton lifetime ($\tau_p>1\times10^{32}\y$) and a small enough…