This article presents a novel method for detecting and studying Feshbach resonances in cold collisions between molecular hydrogen ions and noble gas atoms. The researchers used cold Penning ionization to populate Feshbach resonances and employed ion-electron coincidence detection to resolve all final molecular channels in a tomographic manner. They demonstrated the non-statistical nature of the final-state distribution and showed that each Feshbach resonance has a distinctive signature in the collision outcome.
