Latest results and prospects of the CERN Axion Solar Telescope

Çetin, Serkant Ali (Dogus Author) -- Ezer, C. (Dogus Author) -- Yıldız, Süleyman Cenk (Dogus Author)The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with 4He the collaboration is now immersed in the data taking with 3He, to be finished in 2011. The status of the experiment will be presented, including a preliminary exclusion plot of the first 3He data. CAST is currently sensitive to realistic QCD axion models at the sub-eV scale, and with axion-photon couplings down to the ∼ 2 × 10-10 GeV -1, compatible with solar life limits. Future plans include revisiting vaccuum and 4He configurations with improved sensitivity, as well as possible additional search for non-standard signals from chamaleons, paraphotons or other WISPs. For the longer term, we study the feasibility of an altogether improved version of the axion helioscope concept, with a jump in sensitivity of about one order of magnitude in gaγ beyond CAST

CAST: Recent results & future outlook

Çetin, Serkant Ali (Dogus Author) -- Ezer, Cemile (Dogus Author) -- Yıldız, Süleyman Cenk (Dogus Author) -- Conference full title: 6th Patras Workshop on Axions, WIMPs and WISPs, PATRAS 2010; Zurich; Switzerland; 5 July 2010 through 9 July 2010.The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipes of an LHC dipole. The analysis of data taken so far has shown no signal above the background, thus implying an upper limit to the axion-photon coupling of ga < 0.85 × 10-10GeV -1 at 95% CL for ma < 0.02 eV/c2. Ongoing measurements, with the magnet bores filled with a buffer gas (3He), are improving the sensitivity of the experiment for higher axion masses towards 1 eV/c2. Recent results, new ideas for Axion-Like Particle (WISPs) searches with CAST in the near future and the prospects of a new generation Helioscope are presented here

CAST: Status and latest results

Çetin, Serkant Ali (Dogus Author) -- Full conference title: Proceedings of the 7th Patras Workshop on Axions, WIMPs and WISPs: PATRAS 2011 ; June 27 - July 1, 2011, Mykonos, GreeceIn July 2011 CAST finished the data-taking of its nominal programme having scanned axion masses up to ∼ 1.18 eV/c2. Here we present the first results of the data taken in 2008 first year of the last data-taking campaign when 3He was used inside the magnet bores. No excess of signal over background has been recorded and an upper limit has been set to the axion-to-photon coupling to 2.3×10-10 GeV-1 for axion masses between 0.39 and 0.64 eV. CAST remains the most sensitive axion helioscope and for the first time crosses the benchmark line of the KSVZ model at the upper end of the spectrum.Deutsche Forschungsgemeinschaft, National Science Foundatio

Probing the eV-mass range for solar axions with CAST

Çetin, Serkant Ali (Dogus Author) -- Yıldız, Süleyman Cenk (Dogus Author) -- Conference full title: 2010 IEEE Nuclear Science Symposium conference record (NSS/MIC 2010) : [including the 2010 IEEE Nuclear Science Symposium, Medical Imaging Conference, and the 17th International Workshop on Room-Temperature Semiconductor X-Ray and Gamma-Ray Detectors (RTSD)]; Knoxville, Tennessee, USA, 30 October - 6 November 2010The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, 4He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing 3He phase the studied mass range is now being extended further. In this contribution the final results of CAST's 4He phase will be presented and the current status of the 3He run will be given. This includes latest results as well as prospects of future axion experiments.Nucl. Plasma Sci. Soc. Inst. Electr. Electron. Eng. (NPSS