Test of the Weak Equivalence Principle for antimatter with the AEgIS experiment

by Dr Davide Pagano (UCL)

Wednesday 29 Apr 2015, 13:00 → 14:00 Europe/Brussels

E/3rd floor-E.349 - Seminar room (E.349) (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

The AEgIS experiment at the CERN's Antiproton Decelerator (AD) aims at performing the first precise measurement of the gravitational force on antimatter, by using a beam of antihydrogen atoms. This measurement would probe, for the first time, the Weak Equivalence Principle of General Relativity with antimatter. The production of antihydrogen will be performed by combining the advantages of pulsed charge exchange reaction between highly excited positronium metastable atoms and cold antiprotons that are trapped in a cryogenic Penning trap. Once created, the excited antihydrogen atom will be formed into an anti-atom beam via the use of inhomogeneous electric fields. The deflection of this anti-atom beam due to gravity will be measured by using the Moiré deflectometer gratings and a position sensitive detector. In addition to the measurement of the gravitational interaction between matter and antimatter, longer term plans also include spectroscopy measurements. Comparisons of hydrogen and antihydrogen spectroscopy would be a high-precision test of CPT symmetry. An overview of the physics goals, of the experimental setup and of the preliminary results from the 2014 data taking is presented.