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

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 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.

Experimental perspectives on the matter-antimatter asymmetry puzzle: developments in electron EDM and [Formula: see text] experiments.

In the search for clues to the matter-antimatter puzzle, experiments with atoms or molecules play a particular role. These systems allow measurements with very high precision, as demonstrated by the unprecedented limits down to [Formula: see text] e cm on electron EDM using molecular ions, and relative measurements at the level of [Formula: see text] in spectroscopy of antihydrogen atoms. Building on these impressive measurements, new experimental directions offer potential for drastic improvements.

A compact low energy proton source.

A low energy proton source for non-neutral plasma experiments was developed. Electrons from a hot filament ionize H2 gas inside a geometrically compensated Penning trap to produce protons via dissociative ionization. A rotating wall electric field destabilizes the unwanted H2+ and H3+ generated in the process while concentrating protons at the center of the trap.

GRASIAN: towards the first demonstration of gravitational quantum states of atoms with a cryogenic hydrogen beam.

At very low energies, a light neutral particle above a horizontal surface can experience quantum reflection. The quantum reflection holds the particle against gravity and leads to gravitational quantum states (gqs). So far, gqs were only observed with neutrons as pioneered by Nesvizhevsky and his collaborators at ill.