Coincidence analysis in ANTARES: Potassium-40 and muons

A new calibration technique using natural background light of sea water has been recently developed for the ANTARES experiment. The method relies on correlated coincidences produced in triplets of optical modules by Cherenkov light of beta-particles originated from Potassium-40 decays. A simple but powerful approach to atmospheric muon flux studies is currently being developed based on similar ideas of coincidence analysis. This article presents the two methods in certain detail and explains their role in the ANTARES experiment.