High-precision determination of the electric and magnetic radius of the proton

Abstract

Using dispersion theory with an improved description of the two-pion continuum based on the precise Roy-Steiner analysis of pion-nucleon scattering, we analyze recent data from electron-proton scattering. This allows for a high-precision determination of the electric and magnetic radius of the proton, rE=(0.838−0.004+0.005−0.003+0.004)fm and rM=(0.847±0.004±0.004)fm, where the first error refers to the fitting procedure using bootstrap and the data while the second one refers to the systematic uncertainty related to the underlying spectral functions.