The size of the proton: Closing in on the radius puzzle

Abstract

We analyze the recent electron-proton scattering data from Mainz using a dispersive framework that respects the constraints from analyticity and unitarity on the nucleon structure. We also perform a continued fraction analysis of these data. We find a small electric proton charge radius, rpE = 0.84+0.01-0.01 fm, consistent with the recent determination from muonic hydrogen measurements and earlier dispersive analyses. We also extract the proton magnetic radius, rpM = 0.86+0.02-0.03 fm, consistent with earlier determinations based on dispersion relations. © Società Italiana di Fisica / Springer-Verlag 2012.