DAMA/LIBRA-phase1 results and perspectives of the phase2

Abstract

The results obtained with the total exposure of 1.04 ton × yr collected by DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles are summarized. The DAMA/LIBRA-phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton × yr, corresponding to 14 annual cycles) give evidence at 9.3 σ C.L. for the presence of Dark Matter (DM) particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radio-pure NaI(Tl) target. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. The same data of DAMA/LIBRA-phase1 have also been analyzed searching for possible DM second-order diurnal effect; at present, the DM diurnal modulation amplitude - expected because of the Earth diurnal motion - evaluated on the basis of the DAMA Dark Matter annual modulation results is below the reached experimental sensitivity. Some of the perspectives of the presently running DAMA/LIBRA-phase2 are outlined.