The ENUBET positron tagger prototype: construction and testbeam performance

TL;DR

This paper presents the construction and testbeam performance of the ENUBET positron tagger prototype, a calorimeter with timing capabilities designed for neutrino physics, demonstrating promising results in energy resolution and particle discrimination.

Contribution

The paper introduces a novel calorimeter prototype with a $t_0$-layer for timing and photon discrimination, tested in a beam for neutrino applications.

Findings

Achieved good electron energy resolution and linearity.

Demonstrated effective muon and hadron shower response.

Validated the $t_0$-layer's light yield and particle separation capabilities.

Abstract

A prototype for the instrumented decay tunnel of ENUBET was tested in 2018 at the CERN East Area facility with charged particles up to 5 GeV. This detector is a longitudinal sampling calorimeter with lateral scintillation light readout. The calorimeter was equipped by an additional "$t_0$-layer" for timing and photon discrimination. The performance of this detector in terms of electron energy resolution, linearity, response to muons and hadron showers are presented in this paper and compared with simulation. The $t_0$-layer was studied both in standalone mode using pion charge exchange and in combined mode with the calorimeter to assess the light yield and the 1 mip/2 mip separation capability. We demonstrate that this system fulfills the requirements for neutrino physics applications and discuss performance and additional improvements.