Proton's magnetic radius - The next frontier

Our recent publication challenges the accepted value for the proton magnetic size based on a new theoretical framework and high precision experimental data.

In the last years the proton's size has been a subject of very intense debate. The different values extracted for the proton's charge radius with different methods opened the possibility of finding new physics without need of building big colliders needed to reach high energies. However, the solution of the "Proton Radius Puzzle" after PRad measurements seems to discard any contribution from physics beyond the standard model (#newphysics).

Our extraction from precision electron-proton scattering data yielded a value of 0.850(1)(10) fm

After closing this puzzle, the magnetic radius is emerging as new topic to investigate, and there are new experiments planned to extract this quantity. Our work, posted recently on the arXiv, responds to the demand of several groups needed a reliable extraction of this quantity from rigorous theoretical methods. Our extraction from precision electron-proton scattering data yielded a value of 0.850(1)(10) fm, where the first error is from statistical origin and the second one from theory. This value is very different from the RPP 2018 recommended value, and will trigger for sure some interesting debates in the near future.