The last results in the hunt for the axion of CAST at CERN have been published last week in Nature Physics (open access). The result has been enabled by the availability of a new detection system, composed by a new x-ray telescope coupled to an ultra-low background Micromegas detectors (dubbed IAXO pathfinder system) developed as part of the T-REX project. The system enjoys the best signal-to-noise ratio of any other previous detector in the experiment an is one of the main milestones in the roadmap to prepare the next generation axion helioscope IAXO (the International Axion Observatory).
The corresponding author of the paper is the UNIZAR scientist and T-REX PI Igor G. Irastorza. The published limit on the axion-photon coupling is the first CAST limit that is competitive with the bounds set by astrophysics.
The result has had some impact in the local media. Some links are gathered below: