Related papers: Proton Stability and Superstring Z'
It is noted that, but for one missing piece -- proton decay -- the evidence in support of grand unification is now strong. It includes: (i) the observed family-structure, (ii) the meeting of the gauge couplings, (iii) neutrino-oscillations,…
In minimal supersymmetric SU(5) models, the proton can decay through dimension 5 operators. Since this decay depends directly on the supersymmetric soft masses, it will be constrained by other observables which depend on the soft masses,…
In the supersymmetric grand unified theories (SUSY GUTs), gauge bosons associated with the unified gauge group induce proton decay. We investigate the proton decay rate via the gauge bosons in the SUSY GUTs under the two situations; one 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…
A new supersymmetric standard model based on N=1 supergravity is constructed, aiming at natural explanation for the proton stability without invoking an ad hoc discrete symmetry through R parity. The proton is protected from decay by an…
In this short note we describe the symmetry responsible for absolute, nonperturbative proton stability in the Standard Model. The SM with $N_c$ colors and ${N_g}$ generations has an exact, anomaly-free, generation-independent, global…
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,…
The instability of protons is a crucial prediction of supersymmetric GUTs. We review the decay in minimal supersymmetric SU(5), which is dominated by dimension-five operators, and discuss the implications of the failure of Yukawa…
We present our best estimates of the uncertainties due to heavy particle threshold corrections on the unification scale $M_U$, intermediate scale $M_I$ and coupling constant Alpha_U in the minimal non-supersymmetric SO(10) models. Using…
In the standard model the proton is protected from decay naturally by gauge symmetries, whereas in the ordinary minimal supersymmetric standard model an ad hoc discrete symmetry is imposed for the proton stability. We present a new…
It is well known that in single step breaking of R-parity conserving SUSY SO(10) that needs the Higgs representations $126+\bar 126$ the GUT-gauge coupling violates the perturbative constraint at mass scales few times larger than the GUT…
The supersymmetric extension of the standard model suffers from a problem of baryon-number violation. Discrete (and global) symmetries introduced to protect the proton are unstable under gravitational effects. We add a gauged $U(1)_X$ to…
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.…
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 discuss a supersymmetric extension of the standard model with an extra U(1) gauge symmetry. In this model, the proton stability is guaranteed by the gauge symmetry without invoking R parity. The gauge symmetry breakdown automatically…
Abelian non-topological solitons with Baryon and/or Lepton quantum numbers naturally appear in the spectrum of the minimal supersymmetric standard model. They arise as a consequence of the existence of flat directions in the potential…
We present a locally supersymmetric extension of the minimal supersymmetric Standard Model (MSSM) based on the gauge group $SU(3)_C\times SU(2)_L\times U(1)_Y\times U(1)^\prime$ where, except for the supersymmetry breaking scale which is…
Grand Unified Theories (GUT) predict proton decay as well as the formation of cosmic strings which can generate gravitational waves. We determine which non-supersymmetric $SO(10)$ breaking chains provide gauge unification in addition to a…
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…
We propose a novel theoretical framework in which proton decay is induced by the dark matter. While proton decay requires violation of the $B+L$ symmetry, dark matter stability often relies on the presence of an unbroken symmetry. These…