From the cosmos to the sea Dynamic calibration and dark matter searches with the KM3NeT neutrino telescope

KM3NeT is a neutrino telescope located deep in the waters of the Mediterranean Sea. Neutrinos are detected indirectly through the products of their interactions, which produce Cherenkov radiation. The telescope consists of two distinct infrastructures: KM3NeT/ORCA, dedicated to measuring atmospheric neutrino oscillations, and KM3NeT/ARCA, designed to detect neutrinos originating from astrophysical sources.
Due to its underwater location and flexible structure, the KM3NeT detector moves with deep-sea currents. However, accurately reconstructing the signals from neutrino interactions requires precise knowledge of the position and orientation of its detection elements. This thesis presents and characterises the dynamic calibration methods developed to achieve the envisaged accuracy.
One of the enduring mysteries in physics is the nature of dark matter; improving our understanding of it is a central goal of this thesis. Among the leading theoretical candidates for dark matter are Weakly Interacting Massive Particles (WIMPs), which are the focus of this work. Using data collected with the existing partial configurations of the KM3NeT/ARCA detector, a search was conducted for neutrino signals from WIMP annihilations in the Galactic Center. Although no significant excess of cosmic neutrinos was observed, the analysis allowed constraints to be placed on possible WIMP properties. Additionally, the sensitivity of the completed KM3NeT/ARCA telescope was estimated.