Anti-hydrogen spectroscopy with the ATRAP experiment

by Dr Ghanshyambhai Khatri (Northwestern University/Harvard Physics Department)

Monday Apr 9, 2018, 11:00 AM → 11:45 AM Europe/Zurich

H51 (HIT)

According to the best description of modern physics, the big bang created essentially equal amounts of antimatter and matter. As the universe cooled, the particles made of antimatter and matter should have annihilated each other as they collided. Trying to understand the great mystery of how and why a whole universe survived despite our "predictions" to the contrary has stimulated searches for tiny and unexpected differences between antimatter and matter. Precision spectroscopy of antihydrogen promises to be one of the most stringent tests to date of CPT symmetry. One of the primary goals of the ATRAP experiment, located at the antiproton decelerator (AD) facility of CERN, is to perform precision spectroscopy on the 1S-2S two photon transition in antihydrogen for comparison to hydrogen precision measurements. Trapped antihydrogens in a Penning-Ioffe trap have a large bias and gradient contributing to significant spread due to Zeeman shifts as the antihydrogen orbits in the magnetic trap. The ATRAP collaboration is working on laser cooling of antihydrogen on the 121 nm Lyman alpha line (1S-2P) in order to reduce this spread for more precise 1S-2S spectroscopy. This lecture describes antimatter containment in "traps" - containers with no walls - and illustrates the way that antimatter and matter are most precisely compared in the ATRAP experiment.