Smorra, C.; Mooser, A.; Besirli, M.; Bohman, M.; Borchert, M.J. et al.: Observation of individual spin quantum transitions of a single antiproton. In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 769 (2017), S. 1-6. DOI:
https://doi.org/10.1016/j.physletb.2017.03.024