A University of Melbourne researcher analysed data from the Belle experiment, searching for an invisible new particle produced in B meson decays. Published in Physical Review Letters, the study by Dr. Daniel Marcantonio examined data from the Belle particle physics experiment at the KEK laboratory in Japan, which collided electrons with positrons, their antimatter counterparts. The collision energy was tuned to produce B mesons, which are heavy, unstable particles that contain a bottom quark. B mesons are valuable to study because their decay can be sensitive to new, yet-undiscovered particles. Searching for potential dark matter particles Dr Marcantonio searched the Belle data for evidence of “feebly interacting particles” (FIPs), a hypothetical particle that interacts extremely rarely with ordinary matter. Many theories about particle physics predict FIPs, with some theories suggesting that the particles could be candidates for dark matter or as messengers between ordinary matter and a hypothetical “dark sector”. Marcantonio’s analysis studied five different decay channels in B mesons- three of which had never been searched for before- seeking an invisible new particle accompanied …