Light bosons and photospheric solutions to the solar abundance problem

TL;DR

This paper investigates whether light bosons like axions, hidden photons, or chameleons could explain the solar abundance problem by affecting photospheric measurements, and concludes they cannot due to experimental constraints.

Contribution

It provides a comprehensive analysis ruling out known light bosons as solutions to the solar abundance discrepancy based on conversion mechanisms and experimental bounds.

Findings

Resonant axion-photon conversion is not possible in the line-forming regions.

Constraints from experiments exclude the necessary couplings for detectable effects.

Known light bosons cannot resolve the solar abundance problem through photospheric interactions.

Abstract

It is well known that current spectroscopic determinations of the chemical composition of the Sun are starkly at odds with the metallicity implied by helioseismology. We investigate whether the discrepancy may be due to conversion of photons to a new light boson in the solar photosphere. We examine the impact of particles with axion-like interactions with the photon on the inferred photospheric abundances, showing that resonant axion-photon conversion is not possible in the region of the solar atmosphere in which line-formation occurs. Although non-resonant conversion in the line-forming regions can in principle impact derived abundances, constraints from axion-photon conversion experiments rule out the couplings necessary for these effects to be detectable. We show that this extends to hidden photons and chameleons (which would exhibit similar phenomenological behaviour), ruling out known theories of new light bosons as photospheric solutions to the solar abundance problem.