168133 20260127160850.0 doi 10.1007/JHEP12(2025)009 sideral 147701 ART-2025-147701 eng Altenmüller, K. Search for solar axions produced through the axion-electron coupling gae using a new GridPix detector at CAST 2025 We present a search for solar axions produced through the axion-electron coupling (gae) using data from a novel 7-GridPix detector installed at the CERN Axion Solar Telescope (CAST). The detector, featuring ultra-thin silicon nitride windows and multiple veto systems, collected approximately 160 hours of solar tracking data between 2017–2018. Using machine learning techniques and the veto systems, we achieved a background rate of 1.06 × 10−5 keV−1 cm−2 s−1 at a signal efficiency of about 80% in the 0.2 to 8 keV range. Analysis of the data yielded no significant excess above background, allowing us to set a new upper limit on the product of the axion-electron and axion-photon couplings of gae · gaγ < 7.35 × 10−23 GeV−1 at 95% confidence level for axion masses below 10 meV. This result improves upon the previous best helioscope limit and demonstrates the potential of GridPix technology for rare event searches. Additionally, we derived a limit on the axion-photon coupling of gaγ < 9.0 × 10−11 GeV−1 at 95% CL, which, while not surpassing CAST’s best limit, provides complementary constraints on axion models. Access copy available to the general public Unrestricted info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Anastassopoulos, V. Arguedas-Cuendis, S. Aune, S. Baier, J. Barth, K. Bräuninger, H. Cantatore, G. Caspers, F. Castel, J. F. Universidad de Zaragoza (orcid)0000-0003-3532-7540 Çetin, S. A. Christensen, F. Cogollos, C. Dafni, T. Universidad de Zaragoza (orcid)0000-0002-8921-910X Davenport, M. Decker, T. A. Desch, K. Díez-Ibáñez, D. Universidad de Zaragoza Döbrich, B. Ferrer-Ribas, E. Fischer, H. Funk, W. Galán, J. (orcid)0000-0001-7529-9834 García, J. A. Gardikiotis, A. Giomataris, I. Golm, J. Hailey, C. H. Hasinoff, M. D. Hoffmann, D. H. H. Irastorza, I. G. Jacoby, J. Jakobsen, A. C. Jakovcic, K. Kaminski, J. Karuza, M. Kostoglou, S. Krieger, C. Lakic, B. Laurent, J. M. Luzón, G. Universidad de Zaragoza (orcid)0000-0002-5352-1884 Malbrunot, C. Margalejo, C. Universidad de Zaragoza (orcid)0000-0001-6213-5590 Maroudas, M. Miceli, L. Mirallas, H. Universidad de Zaragoza (orcid)0000-0002-9951-8680 Navarro, P. Obis, L. (orcid)0000-0002-7990-2060 Özbey, A. Özbozduman, K. Papaevangelou, T. Pérez, O. Pivovaroff, M. J. Rosu, M. Ruiz-Chóliz, E. (orcid)0000-0002-2417-7121 Ruz, J. (orcid)0000-0002-3253-7027 Schiffer, T. Schmidt, S. Schumann, M. Semertzidis, Y. K. Solanki, S. K. Stewart, L. Vafeiadis, T. Vogel, J. K. (orcid)0000-0002-5850-5517 Zioutas, K. 2004 X Universidad de Zaragoza Dpto. Física Teórica Proy. investigación HCA 2004 390 Universidad de Zaragoza Dpto. Física Teórica Área Física Atóm.Molec.y Nucl. 2025, 12 (2025) J. high energy phys. Journal of High Energy Physics 1126-6708 6757761 http://zaguan.unizar.es/record/168133/files/texto_completo.pdf Versión publicada 1885538 http://zaguan.unizar.es/record/168133/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:168133 articulos driver 2026-01-27-15:01:00 ARTICLE