Constraining Low-Energy Proton Capture on Beryllium-7 through Charge   Radius Measurements
  In this paper, we point out that a measurement of the charge radius of Boron-8 provides indirect access to the S-factor for radiative proton capture on Beryllium-7 at low energies. We use leading-order halo effective field theory to explore this correlation and we give a relation between the charge radius and the S-factor. Furthermore, we present important technical aspects relevant to the renormalization of pointlike P-wave interactions in the presence of a repulsive Coulomb interaction. 
Emil Ryberg, Christian Forss\'en, H.-W. Hammer and Lucas Platter
nucl-th