Philip Rühl Siegen

Photon/Hadron Discrimination in Hybrid Events at the Pierre Auger Observatory(pdf)

The question about the composition of cosmic rays at the highest energies (i.e. above 1 EeV) is a key question in astroparticle physics. The search for ultra-high-energy photons plays an important role not only in astrophysics and particle physics but also in fundamental physics. The Pierre Auger Observatory close to Malargüe, Argentina, is currently the largest air shower experiment for the detection of ultra-high-energy cosmic rays. It uses a variety of detector types to measure air showers simultaneously and independently including a total of 1660 water-Cherenkov detectors distributed over an area of 3000 km² and 27 fluorescence telescopes. In this talk, a method shall be discussed, which uses the information of both, the water-Cherenkov and fluorescence detectors, (Hybrid Events) to derive a criterion for the discrimination between photons and hadrons in the ultra-high-energy cosmic rays.