Monte-Carlo based performance assessment of ASACUSA's antihydrogen detector

TL;DR

This paper presents a Monte-Carlo based performance assessment of a newly developed antihydrogen detector, demonstrating its calibration, event identification, and background suppression capabilities, with improved signal-to-noise ratio.

Contribution

The work introduces a novel antihydrogen detector with detailed Monte-Carlo simulation calibration and performance evaluation, enhancing detection efficiency and background discrimination.

Findings

Cosmic ray background limited to 12 mHz

Detection efficiency of 81% for antihydrogen events

Improved signal-to-noise ratio from 0.22 to 0.26 s^{-1/2}

Abstract

An antihydrogen detector consisting of a thin BGO disk and a surrounding plastic scintillator hodoscope has been developed. We have characterized the two-dimensional positions sensitivity of the thin BGO disk and energy deposition into the BGO was calibrated using cosmic rays by comparing experimental data with Monte-Carlo simulations. The particle tracks were defined by connecting BGO hit positions and hits on the surrounding hodoscope scintillator bars. The event rate was investigated as a function of the angles between the tracks and the energy deposition in the BGO for simulated antiproton events, and for measured and simulated cosmic ray events. Identification of the antihydrogen Monte Carlo events was performed using the energy deposited in the BGO and the particle tracks. The cosmic ray background was limited to 12 mHz with a detection efficiency of 81 %. The signal-to-noise ratio was improved from 0.22 s^{-1/2} obtained with the detector in 2012 to 0.26 s^{-1/2} in this work.