This title appears in the Scientific Report : 2015 

Theoretical constraints and systematic effects in the determination of the proton form factors
Lorenz, I. T. (Corresponding author)
Meißner, Ulf-G. / Hammer, H.-W. / Dong, Y.-B.
Theorie der Starken Wechselwirkung; IAS-4
Theorie der starken Wechselwirkung; IKP-3
Physical Review D Physical review / D, 91 91 (2015 2015) 1 1, S. 014023 014023
[S.l.] Soc. 2015
Journal Article
Computational Science and Mathematical Methods
Please use the identifier: in citations.
Please use the identifier: in citations.
We calculate the two-photon exchange corrections to electron-proton scattering with nucleon and $\Delta$ intermediate states. The results show a dependence on the elastic nucleon and nucleon-$\Delta$-transition form factors used as input which leads to significant changes compared to previous calculations. We discuss the relevance of these corrections and apply them to the most recent and precise data set and world data from electron-proton scattering. Using this, we show how the form factor extraction from these data is influenced by the subsequent inclusion of physical constraints. The determination of the proton charge radius from scattering data is shown to be dominated by the enforcement of a realistic spectral function. Additionally, the third Zemach moment from the resulting form factors is calculated. The obtained radius and Zemach moment are shown to be consistent with Lamb shift measurements in muonic hydrogen.