Speaker
Description
The annihilation of antiprotons is a fundamental process that still lacks a precise description. When the annihilation involves a nucleus, the initially produced pions can trigger various secondary reactions with differing probabilities, significantly increasing the complexity of the interaction. Despite previous extensive experimental and theoretical efforts, existing models are, to varying degrees, inefficient in fully reproducing all aspects of the annihilation mechanism. The antiproton nucleus reactions at rest are particularly relevant to experiments at CERN's Antiproton Decelerator, designed for atomic physics studies and high-precision tests of fundamental symmetries, where antimatter is primarily detected through its annihilation.
In this talk, I will present results from recent measurements of antiproton-nucleus annihilation at rest conducted at the ASACUSA experiment at CERN, using 150 eV slow extracted antiprotons and thin solid targets made of carbon, molybdenum and gold. The multiplicity of minimum ionizing particles and heavy prongs, as well as their energy deposits, will be compared with simulation models from Geant4 and FLUKA, discussing the limitations of each. Additionally, I will introduce a novel project focused on a detailed, systematic study of charged fragment production in antiproton-induced reactions across different nuclei at very low incident energies. This project, currently in preparation, aims at an in-depth investigation of final state interactions and their evolution with atomic number, while simultaneously providing benchmarks and a foundation for refining simulation models.
