Experimental Search for Solar Axions and Chameleons

• Applicant: Professor Dr. Dieter H.H. Hoffmann
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2008 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 74565491

The aim of this proposal is to ensure our participation in the CAST (CERN Axion Solar Telescope) experiment. CAST has been operating since 2003 and has successfully improved the limits for the axion-photon coupling constant (for axion masses < 0,02 eV) by a factor of 6 compared to prior axion helioscopes. Improvements of the detectors used at CAST have been implemented last year, and together with a second x-ray telescope, these improvements have increased our sensitivity for Axion-like particles (ALPs) by a factor of 4-5 as compared to our previous measurements.Recently, the search for elementary particles at CAST has been extended beyond ALPs. In addition, we have started to look for Chameleons, candidate particles for dark energy. The theoretical model for Chameleons predicts electromagnetic coupling via the Primakoff effect, as well as a direct coupling to matter. The search for chameleons is also included in the experimental program of CAST for 2015.This proposal has two research goals. First, we want to participate in the search for solar axions in 2015 by operating the x-ray telescope and taking part in the general operation of CAST. Secondly, a new detector to search for Chameleons has been developed at the INFN in Trieste and will be tested at CAST in 2015. We plan to take part in the installation, commissioning, and operation of this detector.Both experimental programs (the extension of the search for solar axions as well as the search for chameleons) have been reviewed by the SPSC committee at CERN and have been approved in October 2014.

• DFG Programme: Research Grants