Seminari INFN

First results from DAMA/LIBRA-phase2

by Fabio Cappella (INFN Roma)

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

Aula Conversi

Dip. di Fisica - Edificio G. Marconi

The first model independent results obtained by the DAMA/LIBRA-phase2 experiment will be presented. The data have been collected over 6 annual cycles, corresponding to a total exposure of 1.13 tonxyr, deep underground at the Gran Sasso National Laboratory of the INFN. The DAMA/LIBRA-phase2 apparatus, ~250 kg highly radio-pure NaI(Tl), profits from a second generation high quantum efficiency photomultipliers and of new electronics with respect to DAMA/LIBRA-phase1. The improved experimental configuration has also allowed to lower the software energy threshold. The DAMA/LIBRA-phase2 data confirm the evidence of a signal that meets all the requirements of the model independent Dark Matter (DM) annual modulation signature, at 9.5 sigma C.L. in the energy region (1-6) keV. In the energy region between 2 and 6 keV, where data are also available from DAMA/NaI and DAMA/LIBRA-phase1, the achieved C.L. for the full exposure (2.46 tonxyr) is 12.9 sigma. No systematics or side reaction able to mimic the exploited DM signature has been found.