Atmospheric Muon and Neutrino Fluxes at Very High Energy

J.I. Illana (1) , Paolo Lipari , M. Masip (1) , D. Meloni (2)

1 CAFPE and Depto. de Fı'sica Teórica y del Cosmos
2 JMU - Julius-Maximilians-Universität Würzburg

The observation of astrophysical neutrinos requires a detailed understanding of the atmospheric neutrino background. Since neutrinos are produced in meson decays together with a charged lepton, important constraints on this background can be obtained from the measurement of the atmospheric muon flux. Muons, however, can also be produced as μ μ pairs by purely electromagnetic processes. We use the -moment method to study and compare the contributions to the atmospheric muon and neutrino fluxes from different sources (π/ decay, charmed and unflavored hadron decay, and photon conversion into a muon pair). We pay special attention to the contribution from unflavored mesons (η, η, ρ, ωand ϕ). These mesons are abundant in air showers, their lifetimes are much shorter than those of charged pions or kaons, and they have decay branching ratios of order 10- into final states containing a muon pair. We show that they may be the dominant source of muons at E ≳10 TeV.

Mots clés: Muons; Neutrinos; Cosmic Rays

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]

J.I. Illana, Paolo Lipari, M. Masip, D. Meloni. Atmospheric Muon and Neutrino Fluxes at Very High Energy. Astroparticle Physics, 2011, 34 (9), pp.663. ⟨10.1016/j.astropartphys.2011.01.001⟩. ⟨hal-00727164⟩