Limiting SUSY-QCD spectrum and its application for decays of superheavy particles

The supersymmetric generalization of the limiting and Gaussian QCD spectra is obtained. These spectra are valid for $x \ll 1$, when the main contribution to the parton cascade is given by gluons and gluinos. The derived spectra are applied to decaying superheavy particles with masses up to the GUT scale. These particles can be relics from the Big Bang or produced by topological defects and could give rise to the observed ultrahigh energy cosmic rays. General formulae for the fluxes of protons, photons and neutrinos due to decays of superheavy particles are obtained.Comment: 8 pages, revtex, 3 ps figures. v2 minor changes, v3 typo in eq.(15) corrected; version to appear in Phys. Lett.

Ultra high energy neutrinos from hidden-sector topological defects

We study Topological Defects (TD) in hidden (mirror) matter as possible sources of ultra-high energy neutrinos. The hidden/mirror and ordinary matter are assumed to interact very weakly through gravity or superheavy particles. An inflationary scenario is outlined in which superheavy defects are formed in hidden/mirror matter (and not in ordinary matter), and at the same time the density of mirror matter produced at the end of inflation is much smaller than that of ordinary matter. Superheavy particles produced by hidden-sector TD and the products of their decays are all sterile in our world. Only mirror neutrinos oscillate into ordinary neutrinos. We show that oscillations with maximal mixing of neutrinos from both worlds are possible and that values of $\Delta m^2$, needed for for solution of solar-neutrino and atmospheric-neutrino problems, allow the oscillation of ultra-high energy neutrinos on a timescale of the age of the Universe. A model of mass-degenerate visible and mirror neutrinos with maximal mixing is constructed. Constraints on UHE neutrino fluxes are obtained. The estimated fluxes can be 3 orders of magnitude higher than those from ordinary matter. Detection of these fluxes is briefly discussed.Comment: Revtex, 31 page

On gamma and neutrino radiation from Cyg X-3

The production of high energy gamma and neutrino radiation is studied for Cyg X-3. A heating model is proposed to explain the presence of only one gamma-pulse during 4.8 h period of the source. The acceleration mechanisms are discussed. High energy neutrino flux from Cyg X-3 is calculated