Measurement of the average shape of longitudinal profiles of cosmic-rayair showers at the Pierre Auger Observatory

PIERRE AUGER COLLABORATION; C. BONIFAZI

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2019

1475-7516

The profile of the longitudinal development of showers produced by ultra-highenergy cosmic rays carries information related to the interaction properties of the primaryparticles with atmospheric nuclei. In this work, we present the first measurement of theaverage shower profile in traversed atmospheric depth at the Pierre Auger Observatory. Theshapes of profiles are well reproduced by the Gaisser-Hillas parametrization within the rangestudied, forE >1017.8eV. A detailed analysis of the systematic uncertainties is performedusing ten years of data and a full detector simulation. The average shape is quantified usingtwo variables related to the width and asymmetry of the profile, and the results are comparedwith predictions of hadronic interaction models for different primary particles.