Proton charge radius extraction from electron scattering data using dispersively improved chiral effective field theory

We will present an extraction of the proton charge radius from the elastic form factor data using a theoretical frame- work combining chiral effective field theory and dispersion analysis. Complex analyticity in the momentum transfer correlates the behavior of the spacelike form factor in different Q2 regions and permits the use of data up to Q2 ~ 0.5 GeV2 to constrain the radius. The radius appears as a parameter in the theoretical predictions of the form factors at finite Q2 and can be determined by comparing the predictions for different radii with the finite-Q2 data, without extrapolation to Q2 = 0. With this technique, we obtain a radius of 0.844(7) fm, consistent with the high-precision muonic hydrogen results.