# Measurement of antiproton annihilation on Cu, Ag and Au with emulsion films

## TL;DR

This study measures antiproton annihilation particle multiplicities on Cu, Ag, and Au nuclei using emulsion films, comparing results with GEANT4 and FLUKA simulations to improve understanding of low energy annihilation processes.

## Contribution

It provides experimental measurements of annihilation product multiplicities on different nuclei and evaluates the accuracy of simulation models in predicting these results.

## Key findings

- Good agreement with FLUKA simulation for particle multiplicities.
- Measurements on Cu, Ag, and Au nuclei at low antiproton energies.
- Enhanced understanding of hadronization in low energy antiproton annihilations.

## Abstract

The characteristics of low energy antiproton annihilations on nuclei (e.g. hadronization and product multiplicities) are not well known, and Monte Carlo simulation packages that use different models provide different descriptions of the annihilation events. In this study, we measured the particle multiplicities resulting from antiproton annihilations on nuclei. The results were compared with predictions obtained using different models in the simulation tools GEANT4 and FLUKA. For this study, we exposed thin targets (Cu, Ag and Au) to a very low energy antiproton beam from CERN's Antiproton Decelerator, exploiting the secondary beamline available in the AEgIS experimental zone. The antiproton annihilation products were detected using emulsion films developed at the Laboratory of High Energy Physics in Bern, where they were analysed at the automatic microscope facility. The fragment multiplicity measured in this study is in good agreement with results obtained with FLUKA simulations for both minimally and heavily ionizing particles.