Electromagnetic Dissociation at Cosmic-ray Energies

Electromagnetic dissociation (EMD) is a well-known process which has been extensively studied with accelerator beams. On the contrary, the influence of EMD on cosmic-ray propagation in the atmosphere and in the Galaxy is still somewhat unclear. For example, the mass composition is one of the most important ingredients to understand the origin of ultra-high energy cosmic rays. It can be addressed by the measurement of the depth of the maximum of the air shower development (Xmax) and in particular the shower-to-shower fluctuations around its mean. EMD could modified those observables, in particular, for heavy nuclei. Reliable predictions of cross sections, particle yields, and nuclear fragments produced in electromagnetic dissociation interactions at cosmic-ray energies for various projectiles on various targets are presented. The model for predicting EMD cross sections and the subsequent (virtual) photon interactions is briefly described. The model is embedded in the FLUKA code and has already been successfully validated and used at energies from a few GeV/n up to LHC energies. The virtual and real photon interaction models in FLUKA have recently been significantly improved: a brief description of these changes is included. ... mehrThe impact of EMD interactions on cosmic-ray problems is currently being investigated with these tools, and some preliminary results are presented.