Constraints on proton-proton fusion from helioseismology

TL;DR

This paper uses helioseismology data and solar models to experimentally constrain the proton-proton fusion cross-section parameter $L_{1,A}$, which was previously uncertain and only theoretically estimated.

Contribution

It introduces a novel method to determine the two-nucleon parameter $L_{1,A}$ using helioseismology, providing experimental constraints on proton-proton fusion.

Findings

Determined $L_{1,A}$ = 7.0 fm$^{3}$ with a range of 1.6 to 12.4 fm$^{3}$.

Results are consistent with theoretical estimates of $L_{1,A} \\approx$ 6 fm$^{3}$.

Provides a new experimental approach to constrain solar fusion parameters.

Abstract

The proton-proton ($pp$) fusion cross-section found at the heart of solar models is unconstrained experimentally and relies solely on theoretical calculations. Effective field theory provides an opportunity to constrain the $pp$ cross-section experimentally, however, this method is complicated by the appearance of two-nucleon effects in the form of an unknown parameter $L_{1,A}$. We present a method to constrain $L_{1,A}$ using the Standard Solar Model and helioseismology. Using this method, we determine a value of $L_{1,A}$ = 7.0 fm$^{3}$ with a range of 1.6 to 12.4 fm$^{3}$. These results are consistent with theoretical estimates of $L_{1,A} \approx$ 6 fm$^{3}$.