Study of the forward emission of neutral particles in proton-proton interactions with the LHCf experiment

cosmic-ray showers at very high energy are in disagreement and point to different scenarios, both for the composition of cosmic rays beyond the "knee" region and for the possible excess of particles with energy beyond the GZK cut-off. An important contribution to the systematic uncertainty in the reconstruction of the type and kinematics of the primary particles by the analysis of cosmic-ray showers is due to the poor knowledge of the hadronic interactions at extreme energies. The LHCf experiment, briefly described in this paper, is an important tool to calibrate the hadronic interaction models at high energy through a dedicated study at the LHC accelerator. PACS 13.75. Cs - Nucleon-nucleon interactions. PACS 13.85. Ni - Inclusive production with identified hadrons. PACS 13.85. Qk - Inclusive production with identified leptons, photons, or other nonhadronic particles.