Lecturer: Prof. Jeffrey Hangst, Arhus University, Denmark
The ALPHA experiment at the Antiproton Decelerator is unique in its combined ability to produce, trap, and study atoms of antihydrogen - the simplest anti-atom. The Standard Model requires that hydrogen and antihydrogen have the same spectrum. Transition frequencies in hydrogen can be measured with precisions of order 10-15. The precision in antihydrogen at ALPHA is now of order 10-12, making atom/anti-atom comparisons among the most precise, direct tests of fundamental symmetries in Nature.
Also of fundamental interest is the gravitational behaviour of antimatter, the study of which is the goal of the new ALPHA-g experiment. I will discuss the decades of development necessary to achieve the latest groundbreaking results in ALPHA. Among the latter is the demonstration of laser cooling of antihydrogen, published last week in Nature. I will then consider the future of spectroscopy and gravitational studies with antihydrogen in the era of CERN’s brand-new ELENA facility, which will deliver antiprotons to us in August of 2021.