INVESTIGADORES
MOLLERACH Maria Silvia
artículos
Título:
Depths of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Composition Implications
Autor/es:
THE PIERRE AUGER COLLABORATION, INCLUYE S. MOLLERACH
Revista:
PHYSICAL REVIEW D - PARTICLE AND FILDS
Editorial:
American Physical Society
Referencias:
Año: 2014 vol. 90
ISSN:
0556-2821
Resumen:
Using the data taken at the Pierre Auger Observatory between December
2004 and December 2012, we have examined the implications of the
distributions of depths of atmospheric shower maximum (Xmax), using a
hybrid technique, for composition and hadronic interaction models. We do
this by fitting the distributions with predictions from a variety of
hadronic interaction models for variations in the composition of the
primary cosmic rays and examining the quality of the fit. Regardless of
what interaction model is assumed, we find that our data are not well
described by a mix of protons and iron nuclei over most of the energy
range. Acceptable fits can be obtained when intermediate masses are
included, and when this is done consistent results for the proton and
iron-nuclei contributions can be found using the available models. We
observe a strong energy dependence of the resulting proton fractions,
and find no support from any of the models for a significant
contribution from iron nuclei. However, we also observe a significant
disagreement between the models with respect to the relative
contributions of the intermediate components.