Search for 7Li solar axions using resonant absorption in LiF crystal: Final results

The resonance excitation of the 7Li nuclei in a LiF crystal with mass of 553 g by hypothetical axions emitted in the deexcitation of the 7Li nuclei in the Sun was searched for deep underground at the Gran Sasso National Laboratories (LNGS) of INFN (3600 m w.e.). The data collected with a low background HP Ge detector 244 cm3 during 4044h have allowed us to set the limit on the axion mass: ma<8.6 keV (90% C.L.) which is the best one for the 7Li solar axions to-date.