Study of the performance of the NA62 Small-Angle Calorimeter at the DA$\Phi$NE Linac

TL;DR

This paper reports on the testing and performance evaluation of the upgraded Small Angle Calorimeter prototype for the NA62 experiment, focusing on its energy resolution and photon veto efficiency at the DA$\

Contribution

It presents the first detailed performance measurements of the upgraded calorimeter prototype in a beam test setting.

Findings

Energy resolution was successfully measured.

Photon veto efficiency met design expectations.

Prototype performance supports background suppression goals.

Abstract

The measurement of $BR(K^+\to\pi^+\nu\bar{\nu})$ with 10% precision by the NA62 experiment requires extreme background suppression. The Small Angle Calorimeter aims to provide an efficient veto for photons flying at angles down to zero with respect to the kaon flight direction. The initial prototype was upgraded and tested at the Beam Test Facility of the DA$\Phi$NE Linac at Frascati. The energy resolution and the efficiency were measured and are presented.