Search for 14.4 keV Solar Axions from M1 transition of 57Fe with CUORE crystals

Search for 14.4 keV Solar Axions from M1 transition of 57Fe with CUORE crystals. JCAP. 2013, Vol. 05(2013)007

We report the results of a search for axions from the 14.4 keV M1 transition from
57Fe in the core of the sun using the axio-electric effect in TeO2 bolometers. The detectors
are 5×5×5 cm3 crystals operated at about 10 mK in a facility used to test bolometers for the
CUORE experiment at the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 43.65
kg·d of data was made using a newly developed low energy trigger which was optimized to
reduce the energy threshold of the detector. An upper limit of 0.58 c·kg−1·d−1 is established
at 95% C.L., which translates into lower bounds fA  3.12×105 GeV 95% C.L. (DFSZ model)
and fA  2.41 × 104 GeV 95% C.L. (KSVZ model) on the Peccei-Quinn symmetry-breaking
scale, for a value of S = 0.5 of the flavor-singlet axial vector matrix element. These bounds
can be expressed in terms of axion masses as mA  19.2 eV and mA  250 eV at 95% C.L. in
the DFSZ and KSVZ models respectively. Bounds are given also for the interval 0.35  S 
0.55.