Photon decay in UHE air showers: a stringent bound on Lorentz violation

Discussion timeslot (ZOOM-Meeting): 20. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/96969970711
ZOOM-Meeting ID: 96969970711
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/57-New-Physics-CRD-CRI-DM-GAD-GAI-NU-MM-SH/90
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-07/8

Abstract:
'In extensive air showers induced by ultra-high energy (UHE) cosmic rays, secondary photons are expected to be produced at energies far above those accessible by other means. It has been shown that the decay of such photons, as possible in certain theories allowing the violation of Lorentz invariance, can lead to significant changes of the shower development. Based on observations of the average depth of shower maximum $langle X_text{max}rangle$, a stringent bound on the violation of Lorentz invariance has been placed in a previous work. In this contribution, we include the shower-to-shower fluctuations $sigma(X_text{max})$ as an additional observable. The combined comparison of $langle X_text{max}rangle$ and $sigma(X_text{max})$ to shower observations allows a much stricter test of the possible decay of UHE photons, improving the existing bound by a factor 50.'

Authors: Fabian Duenkel | Marcus Niechciol | Markus Risse
Indico-ID: 148
Proceeding URL: https://pos.sissa.it/395/293