Measurement of the atmospheric muon spectrum from 20 to 2000 GeV

The atmospheric muon spectrum between 20 and 2000 GeV was measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 to 58 degrees. Due to the large data set and the good detector resolution, a precision of 2.6% at 100 GeV was achieved for the absolute normalization of the vertical muon flux. The momentum dependence of the ratio of positive to negative muons was obtained between 20 and 630 GeV.Comment: Poster at the XXIII Physics in Collisions Conference (PIC03), Zeuthen, Germany, June 2003, 3 pages, LaTeX, 2 eps figures. PSN FRAP0

Analysis of Longitudinal Air Shower Profiles measured by the Pierre Auger Observatory

We describe the analysis of longitudinal air shower profiles as measured by the fluorescence detectors of the Pierre Auger Observatory and present the measurement of the depth of maximum of extensive air showers, Xmax, with energies >10^18 eV. The measured energy evolution of the average of Xmax and its fluctuations are compared to air shower simulations for different primary particles.Comment: to appear in the Proceedings of the International Symposium on the Recent Progress of Ultra-high Energy Cosmic Ray Observation, Nagoya 201

Uncertainties in the Magnetic Field of the Milky Way

We improve on the model of the Galactic Magnetic Field (GMF) from Jansson \& Farrar (2012), which was constrained using all-sky rotation measures of extragalactic sources and polarized and unpolarized synchrotron emission data from WMAP. We have developed several alternative functional forms for the coherent and random components, used newer synchrotron products from Planck and WMAP and testes new models of the densities of thermal electrons and cosmic-ray electrons. The differences in the resultant GMF models, depending on which parameterization of the field, synchrotron product and electron densities are used, provides a measure of the uncertainty in our inference of the GMF. We discuss the impact of these uncertainties on charged-particle astronomy at ultra-high energies.Comment: 8 pages, 2 figures, to appear in the Proceedings of the 35th International Cosmic Ray Conference 10-20 July, 2017 Bexco, Busan, Kore