Constraining Low-Energy Proton Capture on Beryllium-7 through Charge Radius Measurements

TL;DR

This study links the charge radius of Boron-8 to the low-energy proton capture rate on Beryllium-7, using effective field theory to provide a new indirect method for constraining astrophysical reaction rates.

Contribution

It introduces a theoretical relation between charge radius measurements and the S-factor for proton capture on Beryllium-7, including technical insights on renormalization of P-wave interactions with Coulomb.

Findings

Derived a correlation between charge radius and S-factor.

Provided a framework for indirect constraints on astrophysical reactions.

Addressed technical challenges in renormalizing P-wave Coulomb interactions.

Abstract

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.