[séminaire] Search for the ultra-high energy photons with Pierre Auger Observatory

by Mikhail Stolpovskiy

Tuesday 13 Nov 2018, 11:00 → 12:00 Europe/Paris

The Pierre Auger Observatory is the largest experiment dedicated to the study of the ultra-high energy (UHE) cosmic rays (CR). Recent results of the Observatory include the energy spectrum, mass composition and indications of anisotropies in the arrival direction distributions of the CR with energy above 10^18 eV. However, there are still mysteries, especially regarding the highest energies (up to 10^20 eV), at which the CR flux becomes suppressed. One possible way to address the raised questions is to study the UHE photons. The difficulty is that the expected photon flux in realistic models is very low. Indeed, up to now, no evidence for photon candidate has been found in the data. Hopefully, photon and hadron showers do differ in many aspects and different methods have been developed exploiting these differences. In this seminar we will describe these differences, review the different methods used so far and present a novel and promising analysis that we have developed. We will also discuss the upper limits on the photon flux established by the Observatory.