Charge ratio of muons from atmospheric neutrinos

We calculate the intensities and angular distributions of positive and negative muons produced by atmospheric neutrinos. We comment on some sources of uncertainty in the charge ratio. We also draw attention to a potentially interesting signature of neutrino oscillations in the muon charge ratio, and we discuss the prospects for its observation (which are not quite within the reach of currently planned magnetized detectors).Comment: 6 pages, 4 figures, to be submitted to Physics Letter

Atmospheric Lepton Fluxes

This review of atmospheric muons and neutrinos emphasizes the high energy range relevant for backgrounds to high-energy neutrinos of astrophysical origin. After a brief historical introduction, the main distinguishing features of atmospheric $\nu_\mu$ and $\nu_e$ are discussed, along with the implications of the muon charge ratio for the $\nu_\mu/\bar{\nu}_\mu$ ratio. Methods to account for effects of the knee in the primary cosmic-ray spectrum and the energy-dependence of hadronic interactions on the neutrino fluxes are discussed and illustrated in the context of recent results from IceCube. A simple numerical/analytic method is proposed for systematic investigation of uncertainties in neutrino fluxes arising from uncertainties in the primary cosmic-ray spectrum/composition and hadronic interactions.Comment: 8 pages, 6 figures, for Proceedings of ISVHECRI 2014 This revised version corrects a typo in Eq. 11. There are no changes in the results (the typo was only in the LaTeX, not in the code

A Comparative Study of the Depth of Maximum of Simulated Air Shower Longitudinal Profiles

A comparative study of simulated air shower longitudinal profiles is presented. An appropriate thinning level for the calculations is first determined empirically. High statistics results are then provided, over a wide energy range, (10^14.0 to 10^20.5 eV), for proton & iron primaries, using four combinations of the MOCCA & CORSIKA program frameworks, and the SIBYLL & QGSJET high energy hadronic interaction models. These results are compared to existing experimental data. The way in which the first interaction controls Xmax is investigated, as is the distribution of Xmax.Comment: 13 pages, 5 figures. Accepted by Astroparticle Physics. (Revised according to referee's comments.