Antiproton annihilation at rest in thin solid targets and comparison with Monte Carlo simulations

Claude Amsler, Horst Breuker, Marcus Bumbar, Matti Cerwenka, Giovanni Costantini, Rafael Ferragut, Markus Fleck, Marco Giammarchi, Angela Gligorova, Giulia Gosta, Eric David Hunter, Carina Killian, Bernadette Kolbinger, Viktoria Kraxberger, Naofumi Kuroda, Moritz Lackner, Marco Leali, Giancarlo Maero, Valerio Mascagna, Yasuyuki Matsuda, Stefano Migliorati, Daniel James Murtagh, Amit Nanda, Lilian Nowak, Simon Rheinfrank, Massimiliano Romé, Martin C. Simon, Minori Tajima, Valerio Toso, Stefan Ulmer, Martin van Beuzekom, Luca Venturelli, Alina Weiser, Eberhard Widmann, Yasunori Yamazaki, Johann Zmeskal

Published 2024-07-09Version 1

The mechanism of antiproton-nucleus annihilation at rest is not fully understood, despite substantial previous experimental and theoretical work. In this study we used slow extracted, sub-keV antiprotons from the ASACUSA apparatus at CERN to measure the charged particle multiplicities and their energy deposits from antiproton annihilations at rest on three different nuclei: carbon, molybdenum and gold. The results are compared with predictions from different models in the simulation tools Geant4 and FLUKA. A model that accounts for all the observed features is still missing, as well as measurements at low energies, to validate such models.