First results of the CAST-RADES haloscope search for axions at 34.67 mu eV

Abstract

We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67 mu eV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of g(a gamma) greater than or similar to 4 x 10(-13) GeV-1 over a mass range of 34.6738 mu eV < m(a)< 34.6771 mu eV is set. This constitutes a significant improvement over the current strongest limit set by CAST at this mass and is at the same time one of the most sensitive direct searches for an axion dark matter candidate above the mass of 25 mu eV. The results also demonstrate the feasibility of exploring a wider mass range around the value probed by CAST-RADES in this work using similar coherent resonant cavities. ; Spanish Agencia Estatal de Investigacion (AEI); Fondo Europeo de Desarrollo Regional (FEDER)European Commission [FPA-2016-76978-C3-2-P, FPI BES-2017-079787, PID2019-108122GB-C33]; CERN Doctoral Studentship programme; European Research CouncilEuropean Research Council (ERC)European Commission [ERC-2018-StG-802836, 742104]; DFGGerman Research Foundation (DFG)European Commission [EXC-2094 -390783311]; European Research Council (ERC)European Research Council (ERC)European Commission [ERC-2017-AdG-788781]; Ramon y Cajal FellowshipSpanish Government [2012-10597, PGC2018-095328-B-I00, FSE-DGA2017-2019-E12/7R]; (Gobierno de Aragon/FEDER) (MINECO/FEDER); EU through the ITN Elusives [H2020-MSCA-ITN-2015/674896]; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [SFB-1258]; PROMETEO [II/2014/050]; Generalitat ValencianaGeneralitat ValencianaEuropean CommissionGeneral Electric [FPA2014-57816-P]; European UnionEuropean Commission [690575, 674896]; US Department of Energy by Lawrence Livermore National LaboratoryUnited States Department of Energy (DOE) [DE-AC52-07NA27344] ; We wish to thank our colleagues at CERN, in particular Marc Thiebert from the Surface Treatments Laboratory, as well as the whole team of the CERN Central Cryogenic Lab-oratory for their support and advice in specific aspects of the project. We thank Arefe Abghari for her contributions as the project's summer student during 2018. This work has been funded by the Spanish Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) under project FPA-2016-76978-C3-2-P (supported by the grant FPI BES-2017-079787) and PID2019-108122GB-C33, and was supported by the CERN Doctoral Studentship programme. The research leading to these results has received funding from the European Research Council and BD, JG and SAC acknowledge support through the European Research Council under grant ERC-2018-StG-802836 (AxScale project). BD also acknowledges fruitful discussions at MIAPP supported by DFG under EXC-2094 -390783311. IGI acknowledges also support from the European Research Council (ERC) under grant ERC-2017-AdG-788781 (IAXO+ project). JR has been supported by the Ramon y Cajal Fellowship 2012-10597, the grant PGC2018-095328-B-I00(FEDER/Agencia estatal de investigacion) and FSE-DGA2017-2019-E12/7R (Gobierno de Aragon/FEDER) (MINECO/FEDER), the EU through the ITN Elusives H2020-MSCA-ITN-2015/674896 and the Deutsche Forschungsgemeinschaft under grant SFB-1258 as a Mercator Fellow. CPG was supported by PROMETEO II/2014/050 of Generalitat Valenciana, FPA2014-57816-P of MINECO and by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreements 690575 and 674896. AM is supported by the European Research Council under Grant No. 742104. Part of this work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.