Superheavy particles of masses β1013β1014GeV with lifetimes
β1010β1022years are very interesting, since their decays may
account for the ultra-high energy (UHE) cosmic rays discovered beyond the
Greisen-Zatsepin-Kuzmin cut-off energy EβΌ5Γ1010GeV. We show
that the presence of such long-lived superheavy particles is a generic
prediction of QCD-like SU(N_c) gauge theories with N_f flavors of quarks and
antiquarks and the large number of colors N_c. We construct explicit models
based on supersymmetric SU(N_c) gauge theories and show that if the dynamical
scale Ξβ1013β1014GeV and N_c = 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.Comment: 13 pages, Late