Mass composition of Ultra High Energy Cosmic Rays at the Pierre Auger Observatory.

HERNAN WAHLBERG POR LA COLABORACION PIERRE AUGER

Conferencia; The 2011 Europhysics Conference on High Energy (EPS-HEP 2011).; 2011

The Pierre Auger Observatory is a hybrid instrument which provides a powerful environment for the measurement of different independent experimental observables that carry information on the characteristics of the longitudinal development of ultra-high energy air showers. In this contribution we present a comparison of the results obtained with the fluorescence detector on the depth of shower maximum with complementary information derived from asymmetry properties of the particle signal in the surface detector stations and the depth profile of muon production points, also derived from surface detector data. The dependence of the measurements with energy by comparison to predictions for proton- and iron-induced showers is finally discussed.