AEgIS
The AEgIS experiment (Antimatter Experiment: gravity, Interferometry, Spectroscopy) at CERN's Antiproton Decelerator (AD) is designed to improve our understanding of the fundamental interaction between gravity and antimatter. The main goal is to directly measure the gravitational acceleration (g) on antihydrogen with unprecedented precision to gain crucial insights into the behavior of antimatter under the influence of gravity — a question that is central to clarifying the asymmetry between matter and antimatter in the universe. The experiment achieves this by producing antihydrogen atoms via a charge exchange reaction between cold, trapped antiprotons from AD-6 and positronium atoms. The positronium atoms (e+e-), produced from a positron beam (e+), are excited to Rydberg states with carefully tuned lasers, extending their lifetime and making them suitable for the formation of antihydrogen. A key feature of the AEgIS experimental setup is the use of a moiré deflectometer, a device that measures the gravitational deflection of the antihydrogen beam. When the beam passes through a series of precisely aligned gratings in the deflectometer, a characteristic moiré fringe pattern is created. This pattern, which encodes the trajectory deviations caused by the gravitational forces on the antihydrogen atoms, is detected and analyzed by a position-sensitive detector that achieves sub-micrometer spatial resolution. By examining the deviations and shifts in the Moiré fringes with high precision, the experiment can accurately determine the extent to which the antihydrogen reacts to the Earth's gravity. This method not only provides a direct measurement of g for antihydrogen, but also confirms the effectiveness of advanced interferometric techniques for studying gravitational effects on antimatter systems. The schematic of the AEgIS experiment is shown below and illustrates the complex interplay of physics and engineering required to achieve its groundbreaking goals. More details about the AEgIS experiment can be found HERE.
TBA
In 2023, the J-PET group joined the AEgIS collaboration, bringing their expertise in plastic scintillator-based detection technology. The J-PET team will provide stand-alone detection modules to precisely monitor the trajectory of the antihydrogen beam as it passes through the moiré deflectometer. These modules, equipped with advanced signal readout electronics, provide a portable and scalable solution that complements the AEgIS experimental framework. The central function of these J-PET modules lies in their ability to reconstruct the annihilation points of antihydrogen atoms. When antihydrogen interacts with the material of the deflectometer grids, the annihilation process produces high-energy pions as a result of matter-antimatter annihilation phenomena. These pions contain important information about the spatial and temporal dynamics of the interaction. By detecting and analyzing these pions, the J-PET modules enable precise vertex reconstruction and provide a detailed map of the locations where annihilation events have taken place. For more details, please contact Dr. Sushil Sharma (sushil.sharma@uj.edu.pl, sushil.sharma@cern.ch).