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arXiv · 2407.03828

NuSTAR as an Axion Helioscope

J. Ruz·E. Todarello·J. K. Vogel·F. R. Candón·M. Giannotti·B. Grefenstette·H. S. Hudson·I. G. Hannah·I. G. Irastorza·C. S. Kim·M. Regis·D. M. Smith·M. Taoso·J. Trujillo Bueno
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Abstract

We present a novel approach to investigating axions and axion-like particles (ALPs) by studying their potential conversion into X-rays within the Sun's atmospheric magnetic field. Utilizing high-sensitivity data from the Nuclear Spectroscopic Telescope Array (NuSTAR) collected during the 2020 solar minimum, along with advanced solar atmospheric magnetic field models, we establish a new limit on the axion-photon coupling strength $g_{a\gamma}\lesssim 7.3\times 10^{-12}$~GeV$^{-1}$ at 95\% CL for axion masses $m_a\lesssim 4\times 10^{-7}$\,eV. This constraint surpasses current ground-based experimental limits, studying previously unexplored regions of the axion-photon coupling parameter space up to masses of $m_a\lesssim 3.4\times 10^{-4}$\,eV. These findings mark a significant advancement in our ability to probe axion properties and strengthen indirect searches for dark matter candidates.

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J. Ruz, E. Todarello, J. K. Vogel, F. R. Candón, M. Giannotti, B. Grefenstette, H. S. Hudson, I. G. Hannah, I. G. Irastorza, C. S. Kim, M. Regis, D. M. Smith, M. Taoso, J. Trujillo Bueno. 2024-07-04. NuSTAR as an Axion Helioscope. https://doi.org/10.1103/18sn-hxtb

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