No axions from the Sun

TL;DR

This paper critically examines claims of solar axion detection via X-ray observations, identifying key issues that challenge the interpretation of the signal as evidence of axions or dark matter.

Contribution

It provides a detailed critique of previous claims, highlighting three problems that invalidate the interpretation of the observed X-ray excess as solar axions.

Findings

Identified three problems in the axion interpretation

Demonstrated the signal cannot be from solar axions

Highlighted the need for alternative explanations

Abstract

Preliminary evidence of solar axions in XMM-Newton observations has quite recently been claimed by Fraser et al. as an interpretation of their detection of a seasonally-modulated excess of the X-ray background. Within such an interpretation, these authors also estimate the axion mass to be $m_a \simeq 2.3 \cdot 10^{- 6}$ eV. Since an axion with this mass behaves as a cold dark matter particle, according to the proposed interpretation the considered detection directly concerns cold dark matter as well. So, the suggested interpretation would lead to a revolutionary discovery if confirmed. Unfortunately, we have identified three distinct problems in this interpretation of the observed result of Fraser et al. which ultimately imply that the detected signal - while extremely interesting in itself - cannot have any relation with hypothetical axions produced by the Sun. Thus, a physically consistent interpretation of the observed seasonally-modulated X-ray excess still remains an exciting challenge.