Recent Results from the High Resolution Fly's Eye Experiment

par Andreas Zech (LPNHE)

lundi 20 févr. 2006, 14:00 → 15:00 Europe/Paris

Amphithéâtre

The High Resolution Fly's Eye experiment (HiRes) consists of two air fluorescence detectors, located on top of hills in the desert of Utah. Equipped with mirrors and photomultiplier tubes, these detectors observe the extensive air showers that are generated when an ultra-high energy cosmic ray interacts with the atmosphere. The HiRes collaboration has measured the energy spectrum of cosmic rays above 10^{17.2} eV. Two spectral features have been found: The "ankle" is clearly seen at about 10^{18.5} eV. We have also evidence for a suppression of the cosmic ray flux at an energy of about 10^{19.8} eV, where the GZK effect is expected to become apparent in the spectrum. This measurement will be presented in detail, together with the most recent results from composition and anisotropy studies.

Slides zech.pdf