2026/07/29 by S. J. Hollick, M. Giannotti, J. Ruz +16
Physics and Astronomy · #hep-ex #astro-ph.SR
4 pages 3 figures main text, 4 pages 5 figures Supplemental Material
arxiv created 2026/07/29 · arxiv updated 2026/07/31
Solar axion-like particles (ALPs) can be resonantly produced through the conversion of transverse plasmons in the magnetic field of the solar interior, introducing a production mechanism complementary to the conventional Primakoff process. In this Letter, we report the first experimental search for solar ALPs produced through this mechanism. Using an exposure of 625.75 kg×yr from ANAIS-112, we search for the annual modulation of the flux induced by the variation of the Earth--Sun distance, assuming detection through inverse Primakoff conversion in the detector. Modulation amplitudes fitted in 1 keV bins between 1--20 keV are consistent with the absence of modulation, yielding the first constraints on the axion--photon coupling that include the resonant transverse-plasmon flux, gaγ < 1.32× 10-9 GeV-1 (90% C.L.) at ma ≃ 150 eV. This previously unexplored production channel extends the sensitivity of ANAIS-112 in the mass range 35--280 eV, where, for the expected solar magnetic-field models, the transverse-plasmon flux exceeds the Primakoff flux by up to two orders of magnitude.