New Upper Limit on the Axion-Photon Coupling with an Extended CAST Run with a Xe-Based Micromegas Detector

Altenmüller, K.; Anastassopoulos, V.; Arguedas-Cuendis, S.; Aune, S.; Baier, J.; Barth, K.; Bräuninger, H.; Cantatore, G.; Caspers, F.; Castel, J.  f.; Çetin, S.  a.; Christensen, F.; Cogollos, C.; Dafni, T.; Davenport, M.; Decker, T.  a.; Desch, K.; Díez-Ibáñez, D.; Döbrich, B.; Ferrer-Ribas, E.; Fischer, H.; Funk, W.; Galán, J.; 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.; Jakovčić, K.; Kaminski, J.; Karuza, M.; Kostoglou, S.; Krieger, C.; Lakić, B.; Laurent, J.  m.; Luzón, G.; Malbrunot, C.; Margalejo, C.; Maroudas, M.; Miceli, L.; Mirallas, H.; Navarro, P.; Obis, L.; Özbey, A.; Özbozduman, K.; Papaevangelou, T.; Pérez, O.; Pivovaroff, M.  j.; Rosu, M.; Ruiz-Chóliz, E.; Ruz, J.; Schmidt, S.; Schumann, M.; Semertzidis, Y.  k.; Solanki, S.  k.; Stewart, L.; Vafeiadis, T.; Vogel, J.  k.; Zioutas, K.; Null, Null

doi:10.1103/physrevlett.133.221005

Hypothetical axions provide a compelling explanation for dark matter and could be emitted from the hot solar interior. The CERN Axion Solar Telescope has been searching for solar axions via their back conversion to x-ray photons in a 9-T 10-m long magnet directed toward the Sun. We report on an extended run with the International Axion Observatory pathfinder detector, doubling the previous exposure time. The detector was operated with a xenon-based gas mixture for part of the new run, providing technical insights for future configurations. No counts were detected in the 95% signal-encircling region during the new run, while 0.75 were expected. The new data improve the axion-photon coupling limit to 5.8×10−11 GeV−1 at 95% CL (for 𝑚𝑎≲0.02 eV), the most restrictive experimental limit to date.

New Upper Limit on the Axion-Photon Coupling with an Extended CAST Run with a Xe-Based Micromegas Detector / Altenmüller, K.; Anastassopoulos, V.; Arguedas-Cuendis, S.; Aune, S.; Baier, J.; Barth, K.; Bräuninger, H.; Cantatore, G.; Caspers, F.; Castel, J. F.; Çetin, S. A.; Christensen, F.; Cogollos, C.; Dafni, T.; Davenport, M.; Decker, T. A.; Desch, K.; Díez-Ibáñez, D.; Döbrich, B.; Ferrer-Ribas, E.; Fischer, H.; Funk, W.; Galán, J.; 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.; Jakovčić, K.; Kaminski, J.; Karuza, M.; Kostoglou, S.; Krieger, C.; Lakić, B.; Laurent, J. M.; Luzón, G.; Malbrunot, C.; Margalejo, C.; Maroudas, M.; Miceli, L.; Mirallas, H.; Navarro, P.; Obis, L.; Özbey, A.; Özbozduman, K.; Papaevangelou, T.; Pérez, O.; Pivovaroff, M. J.; Rosu, M.; Ruiz-Chóliz, E.; Ruz, J.; Schmidt, S.; Schumann, M.; Semertzidis, Y. K.; Solanki, S. K.; Stewart, L.; Vafeiadis, T.; Vogel, J. K.; Zioutas, K.; Null, Null. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - ELETTRONICO. - 133/2024:22(2024), pp. 221005.1-221005.8. [10.1103/physrevlett.133.221005]