Objective
The absence of the Greisen-Zatsepin-Kuzmin cut-off in the observed spectrum of Ultra High Energy Cosmic Rays (UHE CR) most probably implies new physics for its explanation. The large detectors for high-energy cosmic neutrinos, AMANDA and Baikal, recently at operation, need the theoretical predictions for sources and fluxes. These two problems provide the main motivation for theoretical work in this field. Both of them are closely connected with fundamental physics of cosmology (inflation, dark matter), elementary particle physics (production and decay of superheavy particles, supersymmetric QCD cascades at very large energies) and relativistic astrophysics (acceleration of particles by relativistic shocks).
In the framework of the Project the following problems are planned to study.
(1) Production of superheavy particles at post-inflationary epochs (preheating and reheating) and their decay properties (lifetime and spectrum of the decay products);
(2) Production of ultra high energy particles (photons, protons and neutrinos) by topological defects. Role of photons in propagation of UHE CR and production of extensive air-showers. Generation of UHE CR by resonant interaction of neutrinos in the Large Scale Structures sround the sun (Galactic halo, Local Group, Local Supercluster). Production of ultra high energy neutrinos by topological defects in the hidden (mirror) matter in the universe;
(3) Acceleration of UHE CR by relativistic and ultra-relativistic shocks (Gamma^2 effects);
(4) Relativistic dust grains as ultra high energy particles (acceleration and destruction during the propagation);
(5)Calculation of high energy neutrino fluxes from neutralino annihilation in the sun and the earth, in the framework of different supersymmetric models;
(6)Hidden neutrino sources (stellar clusters in galactic nuclei, bright phase of the galaxies);
(7) Further calculations of atmospheric neutrino fluxes.
We expect:
(1) To clarify the status of superheavy relic particles as the source of UHE CR, calculating the relic abundances of these particles, performing MC simulations for the spectrum and calculating anisotropy;
(2) To prove that high energy mirror neutrino can successfuly explain the observational data for UHE CR, including the observed clustering;
(3) To clarify the situation with acceleration by relativistic shocks;
(4) To find the signature of relativistic dust grains in experiments at low energies;
(5) To extend the calculations of neutrino fluxes from neutralino annihilation for new versions of supersymmetric models and put the restrictions on them.
Our work is based on experience of the older generation (V.Kuzmin - one of the authors of the GZK cutoff, V.Berezinsky - one of the founders of high energy neutrino astrophysics, A.Vilenkin - one of the founders of the theory of topological defects, L.Volkova - one of the pioneers of calculations of atmospheric neutrino flux and others) and activity of the young people.
In 1997 -1998 the participants of our collaboration put forward the new ideas, which are widely discussing in UHE CR: production of UHE CR by relic superheavy particles (V.Kuzmin and V.Rubakov 1997, V.Berezinsky M.Kachelriess and A.Vilenkin 1997), gravitational production of superheavy particles at preheating (V.Kuzmin and I.Tkachev 1998), production of UHE CR by cosmic necklaces, V.Berezinsky and A.Vilenkin 1997).
Call for proposal
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67010 Assergi AQ
Italy