Search

The DAMA/LIBRA experiment, consisting of about 250 kg of highly radio-pure NaI(Tl) target, is running deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.; its main aim is the investigation of Dark Matter (DM) particles in the Galactic halo by means of the model independent DM annual modulation signature. In this paper we briefly summarize the results obtained in its first phase of measurements (DAMA/LIBRA–phase1) lasted for 7 annual cycles with a total exposure of 1.04 ton x year . The DAMA/LIBRA–phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton x year, corresponding to 14 annual cycles) give evidence at 9.3 σ C.L. for the presence of DM particles in the galactic halo. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. At fall 2010 a relevant upgrade of the experiment has been performed: all the PMTs have been replaced by new ones having higher quantum efficiency. After some optimization periods, a new phase of measurement, DAMA/LIBRA–phase2, has began in this new configuration with increased sensitivity. Some of the perspectives of the presently running DAMA/LIBRA–phase2 are mentioned.

The DAMA/LIBRA experiment ($\sim$ 250 kg of highly radio-pure NaI(Tl)) is running deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. Here we briefly recall the results obtained in its first phase of measurements (DAMA/LIBRA--phase1, total exposure: 1.04 ton $\times$ yr). DAMA/LIBRA--phase1 and the former DAMA/NaI (cumulative exposure: $1.33$ ton $\times$ yr) give evidence at 9.3 $\sigma$ C.L. for the presence of DM particles in the galactic halo by exploiting the model-independent DM annual modulation signature. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. At present DAMA/LIBRA--phase2 is running with increased sensitivity., Comment: Proceedings to the 19th Workshop "What Comes Beyond the Standard Models", Bled, July 11. -- 19., 2016

Profiting of the favourable conditions offered by the Gran Sasso underground laboratory and of the several low-background DAMA set-ups, many and competitive results have been obtained for rare processes. Here the main results will be briefly resumed and some more details about the latest activities will be given. In particular, the searches on ββdecays of 106Cd and 116Cd and the perspectives of a complementary investigation on those Dark Matter (DM) candidates inducing just nuclear recoils, by exploiting the directionality approach with the anisotropic ZnWO4 scintillators, will be underlined.

Many experimental observations and theoretical arguments have pointed out that a large fraction of the Universe is composed by Dark Matter particles. Many possibilities are open on the nature and interaction types of such relic particles. In particular, this paper summarizes the main results obtained by exploiting the model independent Dark Matter annual modulation signature for the presence of Dark Matter particles in the galactic halo by DAMA experiment.

Arguments on the investigation of the DarkMatter particles in the galactic halo are addressed. Recent results obtained by exploiting the annual modulation signature are summarized and the perspectives are discussed.

The $\simeq$ 250 kg highly radiopure NaI(Tl) DAMA/LIBRA apparatus, running at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N., is described., Comment: 37 pages, 27 figures

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.

The effect pointed out by A. B. Migdal in the 40's (hereafter named Migdal effect) has so far been usually neglected in the direct searches for WIMP Dark Matter candidates. This effect consists in the ionization and the excitation of bound atomic electrons induced by the recoiling atomic nucleus. In the present paper the related theoretical arguments are developed and some consequences of the proper accounting for this effect are discussed by some examples of practical interest., 14 pages, 6 figures, 2 tables, Int. J. Mod. Phys. A (in publication)

The DAMA/NaI experiment (≃ 100 kg highly radiopure NaI(Tl)) at the Gran Sasso National Laboratory of the I.N.F.N. had the unique feature to effectively investigate the presence of Dark Matter particle in the galactic halo by exploiting the model independent annual modulation signature. With a total exposure of more than 10 5 kg × day, collected over seven annual cycles, it has pointed out at 6.3 σ C.L. an effect which satisfies all the many peculiarities of the signature. Neither systematics nor side reactions able to account for the observed effect were found. No experiment whose result can be directly compared in a model independent way with the experimental one of DAMA/NaI is available so far. Several (but still few with respect to the possibilities) corollary model dependent quests for the candidate particle have also been carried out. At present the second generation DAMA/LIBRA set-up (≃ 250 kg highly radiopure NaI(Tl)) is in operation. Positive model dependent hints have also been pointed out by indirect searches for Dark Matter particles in space experiments and are not in contradiction with DAMA/NaI. Thus, the ongoing of model independent experiment deep underground and the new space experiments foreseen in incoming years will certainly further increase our knowledge of the field.

The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the framework of corollary investigations on WIMP Dark Matter candidates. In fact, the modeling of this existing effect implies a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological arguments are developed and possible implications are discussed at some extent., 16 pages, 10 figures, preprint ROM2F/2007/15, submitted for publication

Some extensions of the Standard Model provide Dark Matter candidate particles which can have a dominant coupling with the lepton sector of the ordinary matter. Thus, such Dark Matter candidate particles ($\chi^{0}$) can be directly detected only through their interaction with electrons in the detectors of a suitable experiment, while they are lost by experiments based on the rejection of the electromagnetic component of the experimental counting rate. These candidates can also offer a possible source of the 511 keV photons observed from the galactic bulge. In this paper this scenario is investigated. Some theoretical arguments are developed and related phenomenological aspects are discussed. Allowed intervals and regions for the characteristic phenomenological parameters of the considered model and of the possible mediator of the interaction are also derived considering the DAMA/NaI data., Comment: 16 pages, 6 figures. Accepted for publication in PRD. One typo corrected

In the present paper the results obtained in the investigation of possible diurnal effects for low-energy single-hit scintillation events of DAMA/LIBRA-phase1 (1.04 ton $\times$ yr exposure) have been analysed in terms of an effect expected in case of Dark Matter (DM) candidates inducing nuclear recoils and having high cross-section with ordinary matter, which implies low DM local density in order to fulfill the DAMA/LIBRA DM annual modulation results. This effect is due to the different Earth depths crossed by those DM candidates during the sidereal day., 22 pages, 9 figures, 1 table; in publication on Eur. Phys. J. C

The results obtained with the total exposure of 1.04 ton x yr collected by DAMA/LrBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. during 7 annual cycles are summarized. The DAMA/LLBRA-phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton x yr, corresponding to 14 annual cycles) give evidence at 9.3 sigma 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(T1) target. The modulation amplitude of the single-hit events in the (2-6) keV energy interval is: (0.0112 +/- 0.0012) cpd/kg/keV; the measured phase is (144 +/- 7) days and the measured period is (0.998 +/- 0.002) yr, values well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. Some of the perspectives of the presently running DAMA/LIBRA-phase2 are outlined.

In this paper another class of Dark Matter candidate particles: the pseudoscalar and scalar light bosonic candidates, is discussed. Particular care is devoted to the study of the processes for their detection (which only involves electrons and photons/X-rays) in a suitable underground experimental set-up. For this purpose the needed calculations are developed and various related aspects and phenomenologies are discussed. In particular, it is shown that - in addition to the WIMP cases already discussed elsewhere - there is also possibility for a bosonic candidate to account for the 6.3 sigma C.L. model independent evidence for the presence of a particle DM component in the galactic halo observed by DAMA/NaI. Allowed regions in these scenarios are presented also paying particular care on the cosmological interest of the bosonic candidate., Comment: 23 pages, 6 figures, 1 table, Int. J. Mod. Phys. A (in press)

The DAMA/LIBRA–phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton [Formula: see text] yr, corresponding to 14 annual cycles) give evidence at 9.3[Formula: see text] 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. Results and comparisons will be shortly recalled. Recent analyses on possible diurnal effects and on the Earth shadowing effect (the latter holds only for some DM candidates) will be mentioned. The analysis of the time distribution of the low-energy single-hit events in DAMA/LIBRA–phase1 is reported for the first time. Finally, some perspectives of the presently running DAMA/LIBRA–phase2 will be mentioned.

This paper shortly summarizes 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. 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. The modulation amplitude of the single-hit events in the (2–6) keV energy interval is: (0.0112 ± 0.0012) cpd/kg/keV; the measured phase is (144 ± 7) days and the measured period is (0.998 ± 0.002) yr, values well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade. Some of the perspectives of the presently running DAMA/LIBRA-phase2 are outlined.

In this paper, the model independent annual modulation effect observed by DAMA during four independent experiments of one annual cycle each (57986 kg $\times$ day total statistics) is analysed in terms of a particle dark matter candidate which can only inelastically scatter by making a transition to a slightly heavier state, as previously suggested in the literature.

This paper summarizes in a simple and intuitive way why the neutrons, the muons and the solar neutrinos cannot give any significant contribution to the DAMA annual modulation results. A number of these elements have already been presented in individual papers; they are recalled here. Afterwards, few simple considerations are summarized which already demonstrate the incorrectness of the claim reported in PRL 113 (2014) 081302., 11 pages, 1 table

The results of a search for possible signal due to Primakoff coherent conversion of solar axions into photons in NaI(Tl) are presented. The experiment has been carried out at the Gran Sasso National Laboratory of INFN; the used statistics is 53437 kg day. The presently most stringent experimental limit on g(a gamma gamma) from this process is obtained: g(a gamma gamma) < 1.7 x 10(-9) GeV-1 (90% C.L.). In particular, the axion mass window m(a) greater than or similar to 0.03 eV, not accessible by other direct methods, is explored and KSVZ axions with mass larger than 4.6 eV are excluded at 90% C.L. (C) 2001 Elsevier Science B.V. All rights reserved.

An investigation of the WIMP annual modulation signature is in progress at the Gran Sasso National Laboratory of the I.N.F.N. by means of the similar or equal to 100 kg NaI(TI) DAMA set-up; the results obtained during four annual cycles have already been published. In this paper we will further address in some details the main arguments, which have allowed us to exclude known systematic effects as a possible source of the annual modulation observed in the rate at very low energy. In particular. the (more recently released) data of the DAMA/NaI-3 and DAMA/NaI-4 running periods are considered as quantitative examples.

Data collected deep underground at the Gran Sasso National Laboratory of INFN by using the similar or equal to 6.5 kg DAMA liquid Xenon scintillator have been analysed to search for nucleon and di-nucleon decays into invisible channels (decay to nu (i) )over bar>(i) or to nu (i) )over bar>(i)nu (i) or to 5 nu (i), etc., with i = e, mu, tau) or disappearance. The considered statistics has been 2257.7 kg x day. The new obtained limits are: tau (p) = 1.9 x 10(24) yr, tau (nn), = 1.2 x 10(25) yr and tau (pp) = 5.5 X 10(23) yr at 90% C.L. The latter values are the same or better than those previously established by the Frejus Collaboration; in particular, the limits for the NN decay into nu (tau) )over bar>(tau) are set for the first time. (C) 2000 Elsevier Science B.V. All rights reserved.

Neutral strongly interacting massive particles (SIMPs) were searched for at the Gran Sasso National Laboratory by using two "planes" of detectors in the similar or equal to 100 kg highly radiopure NaI(T1) DAMA setup. SIMP exclusion plots and model-independent limits on neutral nuclearites have been significantly improved.

The ARGO-YBJ experiment is currently under construction at the Yangbajing Cosmic Ray Laboratory (4300 m a.s.l.).The detector consists of a central carpet, 74 × 78 m2, made of a single layer of Resistive Plate Counters (RPCs), and surrounded by a partially instrumented guard ring for a total instrumented area of about 6700 m2. The digital read-out, performed by means of pick-up electrodes 6.7 × 62 cm2 (strip), allows to measure the charged particle number of small size air showers. The technique of counting the number of fired strips on the ARGO carpet corresponds to operate in the 10÷500 TeV energy region where both direct and indirect measurements on the primary cosmic radiation have been performed. Many composition models have been proposed by different experiments. In this work we discuss the ability of the ARGO detector to discriminate among some models.

Development of low radioactive technique allows to investigate many other rare nuclear and subnuclear processes: double [Formula: see text] decay, rare [Formula: see text] and [Formula: see text] decays, and to search for hypothetical particles and processes like axions, charge nonconserving decays, the nucleon, di-nucleon and tri-nucleon decays into invisible channels, to test the Pauli principle. Here, we present results of the rare processes searches and development of instrumentation for low counting experiments.

Experimental observations and theoretical arguments at Galaxy and larger scales have suggested that a large fraction of the Universe is composed by Dark Matter (DM) particles. This has motivated the DAMA experimental efforts to investigate the presence of such particles in the galactic halo by exploiting a model independent signature with highly radiopure setups deep underground. In this paper, a review of 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 INFN during seven annual cycles is given. The DAMA/LIBRA–phase1 data give evidence for the presence of DM particles in the galactic halo, on the basis of the exploited model independent DM annual modulation signature by using highly radiopure NaI(Tl) target, at 7.5[Formula: see text] C.L. Including also the data of the first generation DAMA/NaI experiment (cumulative exposure 1.33 ton × yr, corresponding to 14 annual cycles), the C.L. is 9.3[Formula: see text] and the modulation amplitude of the single-hit scintillation events in the (2–6) keV energy interval is: (0.0112 ± 0.0012) cpd/kg/keV; the measured phase is (144 ± 7) days and the measured period is (0.998 ± 0.002) yr, values well in agreement with those expected for DM particles. No systematic or side reaction able to mimic the exploited DM signature has been found or suggested by anyone over more than a decade.

New dedicated high quantum efficiency (Q.E.) photomultipliers (PMTs) have been produced by HAMAMATSU company, tested, selected and installed in the DAMA/LIBRA set-up at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. In this paper the results obtained in the measurements of various features of these high Q.E. PMTs are reported, and some performances of DAMA/LIBRA in this new configuration are shown.

The DAMA project is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. In particular, the DAMA/LIBRA (Large sodium Iodide Bulk for RAre processes) set-up consists of highly radiopure NaI(Tl) detectors for a total sensitive exposed mass of ≃250 kg. Recent results, obtained by this set-up by exploiting the model independent annual modulation signature of Dark Matter (DM) particles, have confirmed and improved those obtained by the former DAMA/NaI experiment. A model independent evidence for the presence of Dark Matter particles in the galactic halo is cumulatively obtained at 8.2 σ C.L. No systematics or side reactions able to account for the measured modulation amplitude and to contemporaneously satisfy all the many specific requirements of the signature have been found or suggested by anyone over more than a decade. An example of one of the many possible model dependent corollary quests for the candidate particles and for the related astrophysical, nuclear and particle physics scenarios is presented considering the whole cumulative exposure. Future perspectives are shortly addressed.

DAMA/LIBRA is running at the Gran Sasso National Laboratory of the I.N.F.N.. Here the results obtained with a further exposure of 0.34 ton x yr are presented. They refer to two further annual cycles collected one before and one after the first DAMA/LIBRA upgrade occurred on September/October 2008. The cumulative exposure with those previously released by the former DAMA/NaI and by DAMA/LIBRA is now 1.17 ton x yr, corresponding to 13 annual cycles. The data further confirm the model independent evidence of the presence of Dark Matter (DM) particles in the galactic halo on the basis of the DM annual modulation signature (8.9 sigma C.L. for the cumulative exposure). In particular, with the cumulative exposure the modulation amplitude of the single-hit events in the (2 -- 6) keV energy interval measured in NaI(Tl) target is (0.0116 +- 0.0013) cpd/kg/keV; the measured phase is (146 +- 7) days and the measured period is (0.999 +- 0.002) yr, values well in agreement with those expected for the DM particles., presented at the Int. Conf. Beyond the Standard Models of Particle Physics, Cosmology and Astrophysics (BEYOND 2010), 1-6 February 2010, Cape Town, South Africa

Searches for non-paulian nuclear processes, i.e. processes normally forbidden by the Pauli–Exclusion–Principle (PEP) with highly radiopure NaI(Tl) scintillators allow the test of this fundamental principle with high sensitivity. Status and perspectives are briefly addressed.

Searches for non-paulian nuclear processes, i.e. processes normally forbidden by the Pauli-Exclusion-Principle (PEP) with highly radiopure NaI(Tl) scintillators allow the test of this fundamental principle with high sensitivity. Status and perspectives are addressed.

The low background DAMA/NaI experiment (similar or equal to 100 kg highly radiopure NaI(T1)) at the Gran Sasso National Laboratory of the I.N.F.N. investigated the presence of Dark Matter particle in the galactic halo by exploiting the model independent annual modulation signature. This experiment has collected data over seven annual cycles for a total exposure of more than 10(5) kg x day and has pointed out at 6.3 sigma C.L. a modulation effect satisfying all the many peculiarities of the signature. Several corollary model dependent quests for the candidate particle have also been carried out. At present the second generation DAMA/LIBRA setup (similar or equal to 250 kg highly radiopure NaI(T1)) is in operation. A R&D towards possible 1 ton NaI(T1) set-up is also in progress.

Arguments on the investigation of the Dark Matter particles in the galactichalo are addressed. Recent results obtained by the DAMA/LIBRA set-up –exploitingthemodelindependent annualmodulationsignatureforDarkMatter(DM) particles – are shortly summarized. In fact, the DAMA project is anobservatory for rare processes and it isoperative deep underground at the GranSasso National Laboratory of the I.N.F.N. Its main apparatus is at presentthe DAMA/LIBRA set-up, consisting of 250 kg highly radiopure NaI(Tl)detectors. Its first results confirm those obtained by the former DAMA/NaI,supporting the evidence for Dark Matter presence in the galactic halo at 8.2

The low background DAMA/NaI experiment (' 100 kg highly radiopure NaI(Tl)) at the Gran Sasso National Laboratory of the I.N.F.N. had the unique feature to effectively investigate the presence of Dark Matter particle in the galactic halo by exploiting the model independent annual modulation signature. This experiment has collected data over seven annual cycles for a total exposure of more than 10 kg × day and has pointed out at 6.3 σ C.L. a modulation effect satisfying all the many peculiarities of the signature. Neither systematics nor side reactions able to account for the observed effect were found. Several (but still few with respect to the many possibilities) corollary model dependent quests for the candidate particle have also been carried out. At present the second generation DAMA/LIBRA set-up (' 250 kg highly radiopure NaI(Tl)) is in operation. A R&D towards possible ultimate 1 ton NaI(Tl) experiment is also in progress.

Some extensions of the Standard Model provide Dark Matter candidate particles with sub-GeV mass. These Light Dark Matter particles have been considered for example in Warm Dark Matter scenarios (e.g. the keV scale sterile neutrino, axino or gravitino). Moreover MeV scale DM candidates have been proposed in supersymmetric models and as source of the 511 keV line from the Galactic center. In this paper the possibility of direct detection of a Light Dark Matter candidate is investigated considering the inelastic scattering processes on the electron or on the nucleus targets. Some theoretical arguments are developed and related phenomenological aspects are discussed. Allowed volumes and regions for the characteristic phenomenological parameters of the considered scenarios are derived from the DAMA/NaI annual modulation data., 16 pages, 8 figures, submitted for publication. Corrected typos

The highly radiopure $\simeq$ 250 kg NaI(Tl) DAMA/LIBRA set-up is running at the Gran Sasso National Laboratory of the I.N.F.N.. In this paper the first result obtained by exploiting the model independent annual modulation signature for Dark Matter (DM) particles is presented. It refers to an exposure of 0.53 ton$\times$yr. The collected DAMA/LIBRA data satisfy all the many peculiarities of the DM annual modulation signature. Neither systematic effects nor side reactions can account for the observed modulation amplitude and contemporaneously satisfy all the several requirements of this DM signature. Thus, the presence of Dark Matter particles in the galactic halo is supported also by DAMA/LIBRA and, considering the former DAMA/NaI and the present DAMA/LIBRA data all together (total exposure 0.82 ton$\times$yr), the presence of Dark Matter particles in the galactic halo is supported at 8.2 $\sigma$ C.L.., Comment: 40 pages, 21 figures, 6 tables

The DAMA project develops and uses new/improved low background scintil- lation detectors to investigate the Dark Matter (DM) particle component(s) in the galactic halo and rare processes deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N.. Here some highlights of DAMA/LIBRA (Large sodium Iodide Bulk for Rare processes) as a unique apparatus in direct DM investigation for its full sensitive mass, target material, intrinsic radio-purity, methodological approach and all the controls performed on the experimental parameters are outlined. The DAMA/LIBRA-phase1 and the former DAMA/NaI data (cumulative exposure 1.33 ton × yr, corresponding to 14 annual cycles) have reached a model-independent evidence at 9.3 σ C.L. for the pres- ence of DM particles in the galactic halo exploiting the DM annual modulation signature with highly radio-pure NaI(Tl) target. Some of the perspectives of the presently run- ning DAMA/LIBRA-phase2 are summarised and the powerful tools offered by a model independent strategy of DM investigation are pointed out.

The DAMA/Nal set-up has investigated the annual modulation signature over seven annual cycles achieving 6.3 σ C.L. model independent evidence for the presence of a Dark Matter particle component in the galactic halo. Some of the Physics and Astrophysics topics which can be addressed by DAMA/LIBRA are also introduced

DAMA is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N.. In particular, the DAMA/NaI setup ( 100 kg highly radiopure NaI(Tl)) has effectively investigated the model-independent annual modulation signature. The data of seven annual cycles (total exposure of 107731 kg × day) have offered 6.3 σ C.L. model-independent evidence for the presence of a Dark Matter particle component in the galactic halo. Some corollary model-dependent quests for the candidate particle have been investigated. In particular, in addition to WIMPs, also light bosonic candidates can account for the model independent DAMA/NaI result. At present, the second generation DAMA/LIBRA set-up ( 250 kg highly radiopure NaI(Tl)) is in data taking.

DAMA is an observatory for rare processes based on the development and use of various kinds of radiopure scintillators; it is operative deep underground at the Gran Sasso National Laboratory of the INFN. Several low background setups have been realized and many rare processes have been investigated. In particular, the DAMA/NaI setup (⋍ 100 kg highly radiopure NaI(Tl)) has effectively investigated the model-independent annual modulation signature; the data of seven annual cycles (total exposure of 107731 kg × d) have offered a 6.3σ C.L. model-independent evidence for the presence of a Dark Matter particle component in the galactic halo. Some of the many possible corollary model-dependent quests for the candidate particle have also been investigated. At present, the second-generation DAMA/LIBRA setup (⋍ 250 kg highly radiopure NaI(Tl)) is in operation deep underground. This paper summarizes the main aspects.

Galaxy hierarchical formation theories, numerical simulations, the discovery of the Sagittarius Dwarf Elliptical Galaxy (SagDEG) in 1994 and more recent investigations suggest that the dark halo of the Milky Way can have a rich phenomenology containing non thermalized substructures. In the present preliminary study, we investigate the case of the SagDEG (the best known satellite galaxy in the Milky Way crossing the solar neighbourhood) analyzing the consequences of its dark matter stream contribution to the galactic halo on the basis of the DAMA/NaI annual modulation data. The present analysis is restricted to some WIMP candidates and to some of the astrophysical, nuclear and particle Physics scenarios. Other candidates such as e.g. the light bosonic ones, we discussed elsewhere, and other non thermalized substructures are not yet addressed here., 17 pages, 10 figures, to appear in Eur. Phys. J. C

DAMA is an observatory for rare processes based on the development and use of various kinds of radiopure scintillators; it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.M. Several low background set-ups have been realized and many rare processes have been investigated. In particular, the DAMA/NaI set-up ( similar or equal to 100 kg highly radiopure NaI(T1)) has effectively investigated the model- independent annual modulation signature, obtaining from the data of seven annual cycles (total exposure of 107731 kg x day) a 6.3 sigma C.L. modelindependent evidence for the presence of a Dark Matter particle component in the galactic halo. Moreover, some of the many possible corollary model-dependent quests for the candidate particle have also been investigated. At present, the second generation DAMA/LIBRA set-up ( similar or equal to 250 kg highly radiopure NaI(T1)) is in operation deep underground.