Cosmic collisions at the LHCb experiment
Last week at the 52nd Rencontres de Moriond EW in La Thuile, Italy, the LHCb experiment presented the results of an unprecedented and unusual study. Instead of the usual proton-proton collisions, this time the LHCb detector registered collisions between protons and helium nuclei, which were injected near the interaction point of the experiment. This type of collision can usually only be seen far above the Earth's atmosphere, where cosmic-ray particles – highly energetic particles from outside the Solar System – hit interstellar "dust" primarily made up of hydrogen and helium, and are detected by satellite-based experiments. Scientists want to better understand this process and, in particular, are trying to understand how many antiprotons are created when the highly-energetic cosmic-ray protons hit the helium nuclei of the interstellar medium.