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The project is aimed at the study of the origin and characteristics of the cosmic rays of highest energies on the basis of the current experimental data with the help of novel theoretical developments. The efforts of experimental and theoretical physicists will be unified in order to resolve the puzzles of the ultra-high energy cosmic rays (UHECRs). The proposed research covers systematically all levels of the investigation of UHECRs, from data collecting to theoretical interpretation.

From the experimental end, it is planned to continue collecting data on ultra-high-energy cosmic rays. Exposure will be enlarged and precision of the determination of parameters of the UHECRs will be improved. The energy spectrum will be studied with different components of the shower at very high energies. New experimental techniques will be developed for cosmic ray experiments, among them detectors for extreme-energy cosmic ray observation from Space and detectors for observation of the high-energy muon production heights.

Development of new tools for analysis of extensive air showers will allow to study both systematic errors and fluctuations in the determination of energies, arrival directions, and nature of the primary particles. Individual highest energy events will be analysed in detail.

Next, arrival directions of the various sets of UHECRs will be subjected to several statistical studies. The aim here is to test the conjectures of global anisotropy in the distribution of arrival directions of the highest energy cosmic rays, in particular, the Galactic Center- Anticenter asymmetry, correlations with the large scale structure of the Universe and patterns of geomagnetic field in the distribution of the arrival directions, separately for sub-GZK and super-GZK energies. Another important task is to identify possible astrophysical sources of the ultra-high-energy cosmic rays based on positional correlations and to investigate physical mechanisms, which result in particle acceleration in these sources. From the distribution of arrival directions and from reanalisis of individual events at highest energies, as well as from distributions of high energy muon production heights studied with future Yakutsk detector, it will be possible to gain some information about the nature of the primary particles of UHECRs.

Together, these results will allow to test the conjecture about presence of a new component at the super-GZK energies and to study this component if found. On the other hand, theoretical studies of possible manifestations of new physics and astrophysics in ultra-high-energy cosmic rays will be carried out.

As one of the outputs of the project, questions will be posed and distinctive predictions will be made for coming experiments, which could verify or falsify various models of the origin of the ultra-high energy cosmic rays.


Max-Planck Institute for Physics
Foehringer Ring 6
80805 München

Participants (5)

Moscow State University
Leninskie Gory 1
119992 Moscow
Russian Academy of Sciences Institute for Cosmophysical Research and Aeronomy
Lenin Str. 31
677891 Yakutsk
Russian Academy of Sciences Institute for Nuclear Research
60Th October Anniversary Prospect 7A
117312 Moscow
Swiss Federal Institute of Technology
Unil-epfl 1
1015 Lausanne (Epfl)
Université Libre de Bruxelles
Bd. Du Triomphe
1050 Brussels