IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Measurement of the Depth of Maximum of Extensive Air Showers above 10^18eV
Autor/es:
THE PIERRE AUGER COLLABORATION (T. TARUTINA PERTENECE A LA COLABORACION - ORDEN ALFABETICO)
Revista:
PHYSICAL REVIEW LETTERS
Editorial:
AMER PHYSICAL SOC
Referencias:
Año: 2010 vol. 104 p. 9110101 - 9110107
ISSN:
0031-9007
Resumen:
We describe the measurement of the depth of maximum, Xmax, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10^18 eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106_21^35)g/cm2/decade below 10^{18.24+-0.05}eV, and (24±3) g/cm2/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm2. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.