IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Studies of mass composition with the Pierre Auger Observatory
Autor/es:
A. G. MARIAZZI FOR THE PIERRE AUGER COLLABORATION
Lugar:
Vulcano, Italia
Reunión:
Workshop; Vulcano Workshop 2010 on Frontiers Objects in Astrophysics and Particle Physics; 2010
Resumen:
The knowledge of the mass composition of the ultra high energycosmic rays (UHECR) is a crucial point towards the determination oftheir origin, acceleration and propagation mechanism. A unique fea-ture of the Pierre Auger Observatory is its hybrid nature, where show-ers are observed simultaneously by fluorescence telescopes and waterCherenkov tanks. The combined use of these two detection techniquesprovides cross-calibration and a better event reconstruction accuracy.Ideally all mass-sensitive observables should be combined to maximisethe discrimination, but the 10% duty cycle of the fluorescence detec-tor limits the use of direct measurements of shower maximum at thehighest energies.A variety of experimental variables that can be measured with thewater-Cherenkov detectors of the Pierre Auger Observatory are cur-rently investigated. In particular the use of the risetime of the signalsin the detectors and the azimuthal features of the time distributions areexplored. A correlation of these observables with the position of showermaximum (Xmax), as measured with the fluorescence telescopes, is ob-tained. The mass sensitivity of these variables is demonstrated andtheir application for composition studies is discussed.1
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