HBAR-HFS – Hyperfine Structure of Antihydrogen
The ERC Advanced Grant „HBAR-HFS“, grant agreement no. 291242, awarded by the European Research Council to Prof. Dr. Eberhard Widmann, was active from 2012 to 2017. Its aim was to perform in-beam hyperfine spectroscopy of antihydrogen and to develop the necessary techniques.
For this a beam of polarized hydrogen was created and measurements were done using the apparatus developed for antihydrogen, yielding the most precise measurement of the ground-state hyperfine splitting of hydrogen in a beam with an accuracy of 2.7 ppb. The formation of a sufficiently intense beam of cold ground-state antihydrogen necessary for spectroscopy was not completed and is still ongoing.
