# Characterization of a 5 $5 \times 5$ LYSO Matrix Calorimeter Prototype

#### Abstract

In this paper, we present measurements of the energy and the time resolution of the Lutetium-Yttrium Oxyorthosilicate (LYSO) calorimeter prototype for the Mu2e experiment. The prototype calorimeter matrix consisted of 25, 3 × 3 × 130 mm<sup>3</sup>, LYSO crystals readout by 10 × 10 mm<sup>2</sup> Hamamatsu APDs. The prototype has been tested both with the… (More)