Contribution Poster (A0 portrait)
Search for ultra-high energy photons through preshower effect: study of CTA-La Palma efficiency'
As gamma rays propagate from their sources of production to Earth, radiation-matter interactions can occur, leading to an effective screening of the incident flux. In the PeV-EeV range, the dominant energy loss mechanism for photons is the production of electron-positron pairs. These pairs can emit bremsstrahlung photons as they interact with local electromagnetic fields. These photons can initiate air showers in the Earth atmosphere that gamma-ray telescopes can detect through the emission of Cherenkov radiation. The Cosmic-Ray Extremely Distributed Observatory has taken on the challenging goal to detect such correlated air showers in the hope to open a new observation channel on the Universe. Here, we discuss the preliminary results of multivariate analysis used to discriminate between air showers generated by photon ensembles from air showers produced by cosmic-ray background, taking the example of the next-generation gamma-ray observatory Cherenkov Telescope Array (CTA) in La Palma.