# The proton charge radius extracted from the Initial State Radiation experiment at MAMI

Abstract : We report on a comprehensive reinterpretation of the existing cross-section data for elastic electron-proton scattering obtained by the initial-state radiation technique, resulting in a significantly improved accuracy of the extracted proton charge radius. By refining the external energy corrections we have achieved an outstanding description of the radiative tail, essential for a detailed investigation of the proton finite-size effects on the measured cross-sections. This development, together with a novel framework for determining the radius, based on a regression analysis of the cross-sections employing a polynomial model for the form factor, led us to a new value for the charge radius, which is $(0.870 \pm 0.014_\mathrm{stat.}\pm 0.024_\mathrm{sys.} \pm 0.003_\mathrm{mod.})\,\mathrm{fm}$.
Keywords :
Document type :
Preprints, Working Papers, ...

https://hal.archives-ouvertes.fr/hal-02154216
Contributor : Inspire Hep <>
Submitted on : Wednesday, June 12, 2019 - 6:11:29 PM
Last modification on : Friday, July 19, 2019 - 4:29:12 AM

### Citation

M. Mihovilovič, P. Achenbach, T. Beranek, J. Beričič, J.C. Bernauer, et al.. The proton charge radius extracted from the Initial State Radiation experiment at MAMI. 2019. ⟨hal-02154216⟩

Record views