Cosmic absorption of ultra high energy particles

• Published in: Astrophysics and space science Vol. 361; no. 2; pp. 1 - 11
• Main Authors: Ruffini, R., Vereshchagin, G. V., Xue, S.-S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2016; Springer Nature B.V
• Subjects: Absorption; Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Atoms & subatomic particles; Cosmic rays; Cosmology; Energy loss; Evolution; High energy physics; Mathematical analysis; Mean free path; Neutrinos; Observations and Techniques; Opacity; Original Article; Photons; Physics; Physics and Astronomy; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Universe; Background radiations; Cosmic rays; Neutrino
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-016-2668-5

This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and considering appropriate interactions we derive the mean free path for ultra high energy photons, protons and neutrinos. For photons the relevant processes are the Breit-Wheeler process as well as the double pair production process. For protons the relevant reactions are the photopion production and the Bethe-Heitler process. We discuss the interplay between the energy loss length and mean free path for the Bethe-Heitler process. Neutrino opacity is determined by its scattering off the cosmic background neutrino. We compute for the first time the high energy neutrino horizon as a function of its energy.