Neutrino-induced showers in the ANTARES deep-sea telescope

Reconstruction of neutrino-induced showers, initiated by neutral-current interactions, can extend the sensitivity of the ANTARES detector to all neutrino flavors. A major challenge in reconstructing showers is their selection from an overwhelming background of down-going atmospheric muons. We have developed a shower selection strategy in order to select up-going showers with high efficiency and purity. We have tuned the selection strategy on Monte-Carlo simulations containing the proper amount of background and atmospheric neutrino-induced showers. The obtained results indicate an efficiency of 21% with a purity better than 90% for the shower selection. We applied the selection strategy to ANTARES experimental data and observed a satisfactory performance of the discriminating variables.