COLLOQUIUM "Probing antimatter gravity with trapped antihydrogen" by Chris Rasmussen (CERN)

Friday 29 Sept 2023, 11:00 → 12:00 Europe/Amsterdam

Z011 (CWI/Nikhef)

Update: This Colloquium will include the results published in Nature on 27 September 2023 with the "first direct experiment to actually observe a gravitational effect on the motion of antimatter."

Nature paper: https://www.nature.com/articles/s41586-023-06527-1

Press release: https://home.cern/news/news/physics/alpha-experiment-cern-observes-influence-gravity-antimatter

--

Einstein's Weak Equivalence Principle demands that all objects fall with the same acceleration regardless of their composition, and experiments with ordinary matter have verified this with extraordinary precision. When it comes to antimatter objects though, a definitive experimental test has proved elusive. ALPHA-g is a relatively new experiment at CERN which studies the gravitational acceleration of antihydrogen atoms trapped in a magnetic bottle. In this talk I will describe some of the challenges of measuring the very weak effects of gravity on a single antihydrogen atom, and explain how an antimatter gravity measurement in ALPHA-g is carried out.