Long-Lived Superheavy Particles in Dynamical Supersymmetry-Breaking Models in Supergravity

Superheavy particles of masses ' 1013 − 1014 GeV with lifetimes ' 1010 − 1022 years are very interesting, since their decays may account for the ultra-high energy (UHE) cosmic rays discovered beyond the Greisen-Zatsepin-Kuzmin cutoff energy E ∼ 5 × 1010 GeV. We show that the presence of such long-lived superheavy particles is a generic prediction of QCD-like SU(Nc) gauge theories with Nf flavors of quarks and antiquarks and the large number of colors Nc. We construct explicit models based on supersymmetric SU(Nc) gauge theories and show that if the dynamical scale Λ ' 1013 − 1014 GeV and Nc = 6 − 10 the lightest composite baryons have the desired masses and lifetimes to explain the UHE cosmic rays. Interesting is that in these models the gaugino condensation necessarily occurs and hence these models may play a role of so-called hidden sector for supersymmetry breaking in supergravity.