DAMA/LIBRA-phase1 results and perspectives of the phase2

¹ Dip. di Fisica, Università di Roma “Tor Vergata”, I-00133 Rome, Italy
² INFN, sez. Roma “Tor Vergata”, I-00133 Rome, Italy
³ Laboratori Nazionali del Gran Sasso, I.N.F.N., Assergi, Italy
⁴ Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918/3, 100049 Beijing, China
⁵ Dip. di Fisica, Università di Roma “La Sapienza”, I-00185 Rome, Italy
⁶ INFN, sez. Roma, I-00185 Rome, Italy
⁷ Dip. di Ingegneria Civile e Ingegneria Informatica, Università di Roma “Tor Vergata”, I-00133 Rome, Italy
⁸ University of Jing Gangshan, Jiangxi, China

Published online: 29 May 2015

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.