dr hab. Piotr Homola, IFJ PAN

Cosmic-Ray Extremely Distributed Observatory: new research possibilities in astroparticle physics

Cosmic-Ray Extremely Distributed Observatory (CREDO) enables a strategy for a global analysis of cosmic-ray data oriented on reaching the observational sensitivity to ensembles of particles of cosmic origin correlated in time: so-called cosmic-ray cascades. The CREDO approach defines a pioneer, although natural extension of a standard cosmic-ray research focused so far on single particles uncorrelated in time. Cosmic-ray cascades could be formed both within classical (e.g. products of photon-photon interactions) and exotic scenarios (e.g. result of decay of Super Heavy Dark Matter particles and subsequent interactions) and CREDO asks about the circumstances under which such phenomena can be observed. The spatial extent of some of cosmic-ray cascades that reach Earth might offer a unique signature detectable only with the cosmic-ray infrastructure taken as a global network of detectors, signature invisible for individual observatories. Thus the global approach to the detection of cosmic-ray cascades might be the only realistic option. The existing uncertainties about the available physics models at very high energies (photon structure, electrodynamics, space-time structure) as well as insufficient knowledge about the propagation mechanisms, makes one thinking on the CREDO research strategy like of a wide physics program rather than of a short-term project. A wide program requires a wide community of collaborators and that is why everybody is welcome to contribute to CREDO.