New CAST Limit on the Axion-Photon Interaction

V. Anastassopoulos , S. Aune (1) , K. Barth , A. Belov , H. Bräuninger , G. Cantatore , J.M. Carmona , J.F. Castel , S.A. Cetin , F. Christensen , J.I. Collar , T. Dafni , M. Davenport , T.A. Decker , A. Dermenev , K. Desch , C. Eleftheriadis , G. Fanourakis , E. Ferrer-Ribas (1) , H. Fischer , J.A. Garć Ia , A. Gardikiotis , J.G. Garza , E.N. Gazis , T. Geralis , I. Giomataris (1) , S. Gninenko , C.J. Hailey , M.D. Hasinoff , D.H.H. Hoffmann , F.J. Iguaz , Igor Garcia Irastorza , A. Jakobsen , J. Jacoby , K. Jakovčí C , J. Kaminski , M. Karuza , N. Kralj , M. Krčmar , S. Kostoglou , Ch. Krieger , B. Lakić , J.M. Laurent , A. Liolios , A. Ljubičić , G. Luzón , M. Maroudas , L. Miceli , S. Neff , I. Ortega , T. Papaevangelou (1) , K. Paraschou , M.J. Pivovaroff , G. Raffelt , M. Rosu , J. Ruz , E. Ruiz Chóliz , I. Savvidis , S. Schmidt , Y.K. Semertzidis , S.K. Solanki , L. Stewart , T. Vafeiadis , J.K. Vogel , S.C. Yildiz , K. Zioutas

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers

During 2003--2015, the CERN Axion Solar Telescope (CAST) has searched for $a\to\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. In its final phase of solar axion searches (2013--2015), CAST has returned to evacuated magnet pipes, which is optimal for small axion masses. The absence of a significant signal above background provides a world leading limit of $g_{a\gamma} < 0.66 \times 10^{-10} {\rm GeV}^{-1}$ (95% C.L.) on the axion-photon coupling strength for $m_a \lesssim 0.02$ eV. Compared with the first vacuum phase (2003--2004), the sensitivity was vastly increased with low-background x-ray detectors and a new x-ray telescope. These innovations also serve as pathfinders for a possible next-generation axion helioscope.

Mots clés: axion: solar; axion: mass; CAST; magnet; coupling: (axion 2photon); coupling constant; magnetic field; CERN LHC Coll; sensitivity; background; CERN Lab; experimental results; S029IAG

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Instrumentations et Détecteurs [physics.ins-det]

V. Anastassopoulos, S. Aune, K. Barth, A. Belov, H. Bräuninger, et al.. New CAST Limit on the Axion-Photon Interaction. Nature Phys., 2017, 13, pp.584-590. ⟨10.1038/nphys4109⟩. ⟨hal-01582906⟩