proton

Fermilab’s MINERvA experiment was chosen as one of the nine runners up as part of the Physics World 2023 Breakthrough of the Year. The MINERvA research shows how information about the internal structure of the proton can be gleaned from neutrinos scattering from a plastic target.

From Scientific American, March 16, 2023: Big news about a smaller size: MINERvA researchers used a new and entirely independent method to measure a proton’s radius. The team’s measurement of the proton’s radius was 0.73 femtometer, even smaller than the 0.84-femtometer electric charge radius. In either case, it is almost 10,000 times smaller than a hydrogen atom.