Speaker
Maria Monasor Monasor
(University of Chicago)
Description
Due to its hybrid design, the Pierre Auger Observatory provides a variety of
independent experimental observables for the study of the composition of ultra-high
energy cosmic rays. Ground level measurements from the surface detector allow to
define composition sensitive parameters while the fluorescence detector provide a
direct observation of the depth of maximum development of the longitudinal profile
of air showers. A comparison of the results obtained with both techniques will be
presented. Furthermore, these composition sensitive observables combined with the
large collection area of the Observatory, also provide an excellent opportunity to
search for photons within the hadronic background. These photons are expected to
be produced, for example, from the decay of neutral pions in the standard GZK
process or in exotic scenarios such as "top-down" models. Upper limits on the
fraction of photons above 1 EeV that place severe constraints on "top-down" models
will be also presented.
Primary author
Maria Monasor Monasor
(University of Chicago)
