New measurement with deuterium nucleus confirms proton radius puzzle is real

A large team made up of researchers from across the globe has repeated experiments conducted several years ago that showed a different radius for a proton when it was orbited by a muon as opposed to an electron--a finding dubbed the proton radius puzzle--using a deuterium nucleus this time and has found the same puzzle. In their paper published in the journal Science, the team describes the experiments they conducted, what they found and offer a few possible ideas to help dispel the notion that ...