1 Results of the DAMA experiment at LNGS R. Bernabei a , M. Amato b , P. Belli a , F. Cappella a , R. Cerulli a , C.J. Dai c , H.L. He c , G.Ignesti b , A. Incicchitti b , H.H. Kuang c , J.M. Ma c , F. Montecchia a , F. Nozzoli a , D. Prosperi b * a Dip.to di Fisica, Universit` a di Roma “Tor Vergata” and INFN, sez. Roma2, I-00133 Rome, Italy b Dip.to di Fisica, Universit` a di Roma “La Sapienza” and INFN, sez. Roma, I-00185 Rome, Italy c IHEP, Chinese Academy, P.O. Box 918/3, Beijing 100039, China DAMA is searching for rare processes by developing and using several kinds of radiopure scintillators: in particular, NaI(Tl), liquid Xenon and CaF2 (Eu). Here more recent results are summarized with particular attention to the investigation of the WIMP annual modulation signature. 1. INTRODUCTION DAMA is devoted to the search for rare pro- cesses by developing and using low radioactivity scintillators. Its main aim is the search for relic particles (WIMPs: Weakly Interacting Massive Particles). In addition, due to the radiopurity of the used detectors and of the installations, sev- eral searches for other possible rare processes are also carried out, such as e.g. on exotics, on ββ processes, on charge-non-conserving processes, on Pauli exclusion principle violating processes, on nucleon instability and on solar axions[1–13]. The main experimental set-ups running at present are: the ≃ 100 kg NaI(Tl) set-up, the ≃ 6.5 kg liquid Xenon (LXe) set-up and the so- called “R&D” apparatus. 2. THE LXE EXPERIMENT We pointed out the interest in using liquid Xenon as target-detector for particle dark mat- ter search deep underground since ref. [14]. Sev- eral prototypes were built and related results pub- lished [15]. The final choice was to realize a pure liquid Xe scintillator directly collecting the emit- * Neutron measurements in collaboration with: M. An- gelone, P. Batistoni, M.Pillon (ENEA, C.R. Frascati P.O. Box 65, I-00044 Frascati, Italy). Some of the results on rare processes in collaboration with: V. Yu. Denisov, V. I. Tretyak, O.A. Ponkratenko, Yu. G. Zdesenko (Institute for Nuclear Research, MSP 03680 Kiev, Ukraine). ted UV light and filled with Kr-free Xenon gas iso- topically enriched either in 129 Xe at 99.5% (used since time) or (more recently) in 136 Xe at 68.8%. The detailed description of the set-up and its per- formances have been given in ref. [16]. After preliminary measurements both on elas- tic and inelastic WIMP- 129 Xe scattering [17,18], the recoil/electron light ratio and the pulse shape discrimination capability in a similar pure LXe scintillator have been measured both with Am-B neutron source and with 14 MeV neutron gener- ator [19] and – after some upgrading of the set- up – new results on the WIMP search have been obtained [19,20]. In particular, in ref. [19] the pulse shape discrimination technique has been ex- ploited (see Fig 1), while in ref. [20] (see Fig 2) further results on the inelastic excitation of 129 Xe by Dark Matter particles with spin-dependent coupling has also been searched for improving our previous result of ref. [18]. For the sake of com- pleteness, we remind that very large mass would be necessary to approach a suitable sensitivity when investigating such a WIMP-nucleus inelas- tic scattering. Moreover, in 2000/2001 further measurements on the recoil/electron light ratio have been car- ried out at ENEA-Frascati with 2.5 MeV neutron generator; see ref. [21] for details and compar- isons. Other rare processes have been investigated by