Physicists from the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) Collaboration at CERN have successfully synthesized and studied theoretically predicted but never before verified atoms of pionic helium. Their results mark the first time such spectroscopic measurements have been made on an exotic atom containing a meson. Experimental apparatus used to synthesize pionic helium atoms at the Paul Scherrer Institute. Image credit:...
