High Energy Hadronic Interactions and the Puzzles of the Cosmic Radiation

• Applicant: Dr. Sergey Ostapchenko, Ph.D.
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields ; Astrophysics and Astronomy
• Term: from 2021 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465275045

Progress in high energy astrophysics usually requires an improved understanding of particle production processes in various high energy reactions. In the framework of the project, novel theoretical approaches to the treatment of various aspects of hadronic interactions will be applied to challenging problems of high energy astrophysics, related to investigations of ultra-high energy cosmic rays (UHECRs), measurements of high energy neutrino fluxes, and a detection of extraterrestrial fluxes of antinuclei. In particular, it is planned to analyze the nuclear composition of UHECRs, based on experimental data of giant air shower arrays, and to discriminate thereby between various models for the UHECR origin, using the new QGSJET-III Monte Carlo generator of hadronic interactions and critically assessing the uncertainties of the model predictions. The second research goal is to calculate the atmospheric neutrino background, including the prompt neutrino contribution, using a new approach for the description of the intrinsic charm content of the proton. The obtained results will be applied for a more precise determination of the astrophysical neutrino flux, based on the data of the IceCube observatory, notably, in the most physically interesting PeV energy range corresponding to the cutoff of the observed neutrino spectrum. The third major goal of the project is to obtain maximally constrained predictions for the fluxes of antinuclei from cosmic ray interactions with the interstellar medium and from other astrophysical sources.

• DFG Programme: Research Grants
• International Connection: Norway, USA
• Cooperation Partners: Professor Dr. Michael Kachelrieß; Dr. Igor V. Moskalenko