Comparison between large area PMTs and SiPM arrays deployed in a Liquid Argon Time Projection Chamber at CERN

Liquid argon Time Projection Chambers (LAr-TPCs) are among the most promising detectors for the study of neutrino oscillations. They are composed by a multi-wire drift chamber to collect the charge and a photodetection system to detect the scintillation light, both produced by ionizing charged particles that cross the argon volume. Scintillation light plays a fundamental role for the event reconstruction because it permits to calculate the absolute time $t_0$ of the event and it is also used for triggering purposes. We present a comparison between the performances of large area Photo-Multiplier Tubes (PMTs) and Silicon Photo-Multiplier (SiPM) arrays deployed in a small LAr-TPC exposed to cosmic rays at CERN, both in terms of light collected and timing performances.