Dama

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Abstract

The DAMA project at the Gran Sasso National Laboratories of the I.N.F.N. is an observatory for rare processes thanks to the development and use of large mass highly radiopure scintillator set-ups. The main activity field is the investigation on Dark Matter particles in the galactic halo and the search for several other rare processes (such as bb decay modes in various isotopes, charge-non-conserving processes, Pauli exclusion principle violating processes, nucleon instability, detection of solar axions and search for exotics).

 

Detectors

The main radiopure experimental set-ups of the DAMA project at LNGS are:

  • the DAMA/NaI set-up (~100 kg highly radiopure NaI(Tl)), which has completed its data taking in July 2002. It had as main aim the investigation of the presence of a Dark Matter particle component in the galactic halo by means of the model independent annual modulation signature. With the 0.29 ton x year total exposure it achieved a 6.3 sigma C.L. model independent evidence [1], [2]. Some of the many possible corollary quests for the candidate particle have also been carried out [1], [2], [3], [4], [5], [6], [7], [8]. The same experimental set-up has also obtained several other results on other approaches and on various other rare processes (e.g. solar axion, possible Pauli exclusion principle violation, cluster decay, possible spontaneous transition on nuclei to a superdense state, Q-balls, possible charge non conserving processes, SIMPs and nuclearities, electron stability);
  • the DAMA/LXe set-up (~6.5 kg liquid Xenon), which can take data filled with Kr-free Xenon enriched either in 129Xe or in 136Xe isotopes. It has investigated several rare processes with time passing in the various configurations and is in operation. The main experimental results have been obtained investigating e.g.: dark matter with various approaches, double beta decay in 134Xe and in 136Xe, possible charge non conserving processes, electron stability, possible nucleon, di-nucleon and tri-nucleon decay into invisible channels;
  • the DAMA/R&D set-up, where tests of prototype PMTs and detectors are carried out as well as small scale experiments mainly devoted to the search for double beta decay processes in various isotopes (e.g. 40Ca, 46Ca, 48Ca, 64Zn, 70Zn, 180W, 186W, 106Cd, 108Cd, 114Cd, 136Ce, 138Ce, 142Ce, 130Ba); other rare processes have been also studied, we recall e.g.: dark matter with CaF2 crystal scintillator, rare alpha decay in 151Eu, rare beta decay of 113Cd. Many other measurements are in progress/preparation;
  • the second generation DAMA/LIBRA set-up (Large sodium Iodide Bulk for RAre processes; ~250 kg more radiopure NaI(Tl)) is continuing the investigations of DAMA/NaI with a larger mass and an increased sensitivity. In particular the data of the first four annual cycles (exposure: 0.53 kg x year) have been released in 2008. The results confirm the model independent evidence for the presence of Dark Matter particle in the galactic halo [1]. In February 2010 the data of two further annual cycles have been released [2]and in 2013 [3] the cumulative model independent result of DAMA/LIBRA-phase1 has been released by adding an additional annual cycle. The cumulative exposure collected, considering the 7 annual cycles of DAMA/NaI and the 7 annual cycles of DAMA/LIBRA-phase1, is 1.33 ton x year. The model independent evidence is observed with a statistical significance of 9.3 sigma C.L.. This model independent result is compatible with various Dark Matter candidate particles, interaction types and scenarios. No experiment whose results can be directly compared in a model independent way with these ones is available in the field;
  • the DAMA/Ge set-up dedicated to measurements on samples' radiopurity and on relatively small scale experiments, is operative at the LNGS STELLA facility; is has obtained several interesting results on rare processes. It is continuosly in operation and many new measurements are in preparation;
  • the DAMA/CRYS set-up is a new small scale facility mainly dedicated to the characterization of new prototype detectors;
  • finally a 3-rd generation R&D toward the creation of a possible 1 ton NaI(Tl) set-up, proposed already in 1996, is in progress.

 

Dark matter investigation

The DAMA/NaI and DAMA/LIBRA set-ups have been designed and built to exploit the model independent annual modulation signature and to point out the presence of Dark Matter particles in the galactic halo independently on hypothesized theoretical models. This signature originally suggested in the mid ‘80s by Freese et al. requires that many specific peculiarities are simultaneously satisfied in order to provide unequivocal evidence. In fact, as a consequence of its annual revolution around the Sun, which is moving in the Galaxy, the Earth should be crossed by a larger flux of Dark Matter particles around 2 June (when the Earth orbital velocity is summed to the Sun velocity in the Galaxy) and by a smaller one around 2 December (when the two velocities are opposite). Thus, this signature has a different origin and peculiarities than the seasons on the Earth and than effects correlated with seasons (consider the expected value of the phase as well as the other requirements listed below). The DM annual modulation signature is very distinctive since the effect induced by DM particles must simultaneously satisfy all the following requirements: the rate must contain a component modulated according to a cosine function (1) with one year period (2) and a phase that peaks roughly around about 2nd June (3); this modulation must only be found in a well-defined low energy range, where DM particle induced events can be present (4); it must apply only to those events in which just one detector of many actually “fires” (single-hit events), since the DM particle multi-interaction probability is negligible (5); the modulation amplitude in the region of maximal sensitivity must be < 7% for usually adopted halo distributions (6), but it can be larger in case of some possible scenarios. This approach is very competitive and it needs the realization of an experiment with large mass, high radio-purity and high control of the running conditions, as is the case of the former DAMA/NaI and of the present DAMA/LIBRA experiments.
As mentioned before DAMA/NaI and DAMA/LIBRA have measured an annual modulation effect satisfying all the peculiarities of the considered signature; if the total cumulative data of the two experiments are considered, the measurements refer to 14 annual cycles. In each annual cycle an independent effect of this modulation has been observed. The cumulative exposure of about 1.33 tons x years is several orders of magnitude greater than the exposures typically achieved in this field. The observed modulation effect is highly significant. Neither systematic effects nor side reactions able to mimic the signature were found, no systematic effect able to explain the observed modulation amplitude and to satisfy simultaneously all the requirements of the signature has been found or suggested by anyone over more than a decade. The results obtained by DAMA/NaI and DAMA/LIBRA satisfy all the requirements of the signature and indicate the presence of dark matter particles in our galaxy with high significance. The observed effect is also consistent with a wide range of possible scenarios on the nature of these particles, on characteristics of interaction and on the structure of the galactic halo. In particular, many interpretations of the observed effect in terms of several possible candidates and of various scenarios of particle physics, nuclear physics and astrophysics have been performed so far; other interpretations have been proposed and/or planned. It is worth noting that no experiment whose results can be compared in a model independent way with those of DAMA/NaI and DAMA/LIBRA is available in the field. We also note the currently available model dependent negative results obtained in indirect and direct searches are not in robust conflict with the model independent result of DAMA, while compatibility exists with some possible recent positive hints.
The unique properties and characteristics of DAMA/LIBRA (whose first upgrade has been performed in September 2008, while the second more important one has been carried out in Fall 2010) will also allow in the future the further investigation of the features of the candidate particles and of the astrophysical, nuclear and elementary particle aspects related to the signal characteristics and of the possible second order effects.
The DAMA/LIBRA set-up has also obtained several other results on other approaches and on various rare processes. The experiment has been upgraded and at present DAMA/LIBRA-phase2 is running.

 

Spokesperson
Rita Bernabei (Università Tor Vergata, Roma)
 
 

Some Recent Publications (the complete list is available here)

R.Bernabei, P.Belli, A.Bussolotti, F.Cappella, V.Caracciolo, R.Cerulli, C.J.Dai, A. d'Angelo, A. Di Marco, H.L.He, A. Incicchitti, X.H.Ma, A.Mattei, V.Merlo, F.Montecchia, X.D. Sheng, Z.P.Ye, First model independent results from DAMA/LIBRA-phase2,, Nucl. Phys and Atomic Energy vol. 19, issue 4 (2018) 307-325 [DOI:10.15407/jnpae2018.04.307; arXiv:1805.10486].

R. Bernabei, P. Belli, A. Bussolotti, R. Cerulli, A. Di Marco, V. Merlo, F. Montecchia, F. Cappella, A. d'Angelo, A. Incicchitti, A. Mattei, V. Caracciolo, C.J. Dai, H.L. He, X.H. Ma, X.D. Sheng, Z.P. Ye, New Model independent Results From the First Six Full Annual Cycles of DAMA/LIBRA-Phase2, BLED WORKSHOPS IN PHYSICS VOL. 19, NO. 2 (2018) 27-57.

P. Belli, R. Bernabei, R. S. Boiko, F. A. Danevich, A. Di Marco, A. Incicchitti, D. V. Kasperovych, F. Cappella, V. Caracciolo, V. V. Kobychev, O. G. Polischuk, N. V. Sokur, V. I. Tretyak, R. Cerulli, HALF-LIFE MEASUREMENTS OF 212Po WITH THORIUM-LOADED LIQUID SCINTILLATOR, NUCL. PHYS. AT. ENERGY 19 (2018) 220-226 [doi: 10.15407/jnpae2018.03.220] 

A.S. Barabash, P. Belli, R. Bernabei, F. Cappella, V. Caracciolo, R. Cerulli, D.M. Chernyak, F.A. Danevich, S. d'Angelo, A. Incicchitti, D.V. Kasperovych, V.V. Kobychev, S.I. Konovalov, M. Laubenstein, D.V. Poda, O.G. Polischuk, V.N. Shlegel, V.I. Tretyak, V.I. Umatov, Ya.V. Vasiliev,Final results of the Aurora experiment to study 2beta decay of 116Cd with enriched 116CdWOcrystal scintillators, Phys. Rev. D 98 (2018) 092007. 

R.Bernabei, P.Belli, A.Bussolotti, F.Cappella, V.Caracciolo, R.Cerulli, C.J.Dai, A. d'Angelo, A. Di Marco, H.L.He, A. Incicchitti, X.H.Ma, A.Mattei, V.Merlo, F.Montecchia, X.D. Sheng, Z.P.Ye, First model independent results from DAMA/LIBRA-phase2, Universe 4 (2018) 116 (doi:10.3390/universe4110116), and arXiv:1805.10486. 

R. Cerulli, P. Villar, F. Cappella, R. Bernabei, P. Belli, A. Incicchitti, A. Addazi, Z. Berezhiani, DAMA annual modulation and mirror Dark Matter, Eur. Phys. J. C 77 (2017) 83, [arXiv:1701.08590]

R. Bernabei, P. Belli, A. d'Angelo, S. d'Angelo, A. Di Marco, F. Montecchia, A. Incicchitti, F. Cappella, V. Caracciolo, R. Cerulli, C.J. Dai, H.L. He, H.H. Kuang, X.H. Ma, X.D. Sheng, R.G. Wang and Z.P. Ye, Highlights of DAMA/LIBRA,EPJ Web of Conferences 126 (2016) 02014

Int. J. of Mod. Phys. A invited issue dedicated to DAMA:

  • R. Bernabei, "The DAMA project", Int.J. of Mod.Phys. A 31 (2016) 1642001 (7 pag.) 
  • R. Bernabei, P. Belli, A. Incicchitti, A. Mattei, F. Cappella, R. Cerulli, C.J. Dai, X.H. Ma, Z. P. Ye, "The highly radiopure NaI(Tl) DAMA/LIBRA setup", Int.J. of Mod.Phys. A 31 (2016) 1642002 (20 pag.) 
  • R. Bernabei, P. Belli, A. Incicchitti, C.J. Dai, "Adopted low background techniques and analysis of radioactive trace impurities", Int.J. of Mod.Phys. A 31 (2016) 1642003 (14 pag.) 
  • F. Cappella, V. Caracciolo, R. Cerulli, A. Bussolotti, A. Mattei, "The calibration and the monitoring/alarm system", Int.J. of Mod.Phys. A 31 (2016) 1642004 (18 pag.) 
  • P. Belli, A. Bussolotti, V. Caracciolo, R. Cerulli, C. J. Dai, X. H. Ma, "The electronics and DAQ system in DAMA/LIBRA", Int.J. of Mod.Phys. A 31 (2016) 1642005 (14 pag.) 
  • R. Bernabei, P. Belli, S. d'Angelo, A. Di Marco, F. Montecchia, A. d'Angelo, A. Incicchitti, D. Prosperi, F. Cappella, V. Caracciolo, R. Cerulli, C.J. Dai, H.L. He, H.H. Kuang, X.H. Ma, X.D. Sheng, R.G. Wang, Z.P. Ye, "DAMA/LIBRA phase1 model independent results", Int.J. of Mod.Phys. A 31 (2016) 1642006 (22 pag.) 
  • A. Di Marco, F. Cappella, R. Cerulli, "Other rare processes with DAMA/LIBRA", Int.J. of Mod.Phys. A 31 (2016) 1642007 (12 pag.) 
  • R. Bernabei, P. Belli, A. Di Marco, A. d'Angelo, A. Incicchitti, F. Cappella, R. Cerulli, C.J. Dai, X.H. Ma, Z.P. Ye, "Investigation on possible systematics and side processes", Int.J. of Mod.Phys. A 31 (2016) 1642008 (38 pag.) 
  • R. Bernabei, P. Belli, A. Incicchitti, R. Cerulli, C.J. Dai, X.H. Ma, Z.P. Ye, "On corollary model-dependent analyses and comparisons",  Int.J. of Mod.Phys. A 31 (2016) 1642009 (14 pages)   DOI: 10.1142/S0217751X16420094
  • R. Bernabei, P. Belli, A. Incicchitti, F. Cappella, R. Cerulli, C.J. Dai, H.L. He, H.H. Kuang, X.H. Ma, X.D. Sheng, R.G. Wang, Z.P. Ye, R.S. Boiko, F.A. Danevich, V.V. Kobychev, D.V. Poda, O.G. Polischuk, V.I. Tretyak, "Main results and perspectives on other rare processes with DAMA experiments", Int.J. of Mod.Phys. A 31 (2016) 1642010 (36 pag.) 
  • R. Bernabei, P. Belli, A. Incicchitti, R. Cerulli, C.J. Dai, X.H. Ma, "Towards the next and far future", Int.J. of Mod.Phys. A 31 (2016) 1642011 (2 pag.)

R. Bernabei, Particle dark matter direct detection, Int. J. of Mod. Phys. D 25 (2016) 1630018

P. Belli, R. Bernabei, V.B. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, D.M. Chernyak, F.A. Danevich, S. d'Angelo, A. Di Marco, A. Incicchitti, M. Laubenstein, V.M. Mokina, D.V. Poda, O.G. Polischuk, V.I. Tretyak, I.A. Tupitsyna, Search for 2β decay of 106Cd with enriched 106CdW4 crystal scintillator in coincidence with four HPGe detectors, Phys. Rev. C 93 (2016) 045502 [arXiv:1603.06363]

P. Belli, R. Bernabei, V.B. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, D.M. Chernyak, F.A. Danevich, S. d'Angelo, A. Di Marco, A. Incicchitti, M. Laubenstein, V.M. Mokina, D.V. Poda, O.G. Polischuk, V.I. Tretyak, I.A. Tupitsyna, Search for 2β decay of 106Cd with enriched 106CdW4 crystal scintillator in coincidence with four HPGe detectors, arXiv:1603.06363 accepted for publication on Phys. Rev. C

R. Bernabei, P. Belli, A. Incicchitti, F. Cappella, R. Cerulli, Liquid noble gases for dark matter searches: an updated survey, Int. J. of Mod. Phys. A 30 (2015) 1530053-1 (76 pages)

A. Addazi, Z. Berezhiani, R. Bernabei, P. Belli, F. Cappella, R. Cerulli, A. Incicchitti, DAMA annual modulation effect and asymmetric mirror matter, Eur. Phys. J. C 75 (2015) 400 [arXiv:1507.04317]

R. Bernabei, P. Belli, S. d'Angelo, A. Di Marco, F. Montecchia, A. d'Angelo, A. Incicchitti, F. Cappella, V. Caracciolo, R. Cerulli, Investigating Earth Shadowing effect with DAMA/LIBRA-phase1, Eur. Phys. J. C 75 (2015) 239 [arXiv:1505.05336] 

P. Belli, R. Bernabei, F. Cappella, R. Cerulli, F. Danevich, V. Yu. Denisov, A. d'Angelo, A. Incicchitti, V.V. Kobychev, D.V. Poda, O.G. Polischuk, V.I. Tretyak, Search for long-lived superheavy eka-tungsten with radiopure ZnWO4 crystal scintillator, Physica Scripta 90 (2015) 085301 [arXiv:1504.07438]

R.Bernabei, P.Belli, F.Cappella, V.Caracciolo, R.Cerulli, C.J. Dai, A. d'Angelo, S. d'Angelo, A. Di Marco, H.L.He, A. Incicchitti, H.H.Kuang, X.H.Ma, F.Montecchia, X.D. Sheng, R.G.Wang and Z.P.Ye, No role for neutrons, muons and solar neutrinos in the DAMA annual modulation results, Eur. Phys. J. C 74 (2014) 3196. 

R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, R. Cerulli, C.J. Dai, A. d'Angelo, S. d'Angelo, A. Di Marco, H.L. He, A. Incicchitti, X.H. Ma, F. Montecchia, D. Prosperi, X.D. Sheng, R.G. Wang, Z.P. Ye, DAMA/LIBRA results and perspectives of phase 2, Nucl. Instr. & Meth. A 742 (2014) 177.

R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, S. Castellano, R. Cerulli, C.J. Dai, A. d'Angelo, S. d'Angelo, A. Di Marco, H.L. He, A. Incicchitti, H.H. Kuang, X.H. Ma, F. Montecchia, D. Prosperi, X.D. Sheng, R.G. Wang, Z.P. Ye, Model independent result on possible diurnal effect in DAMA/LIBRA-phase1, Eur. Phys. J. C 74 (2014) 2827 [arXiv:1403.4733].

P. Belli, R. Bernabei, F. Cappella, V. Caracciolo, R. Cerulli, F.A. Danevich, A. Di Marco, A. Incicchitti, D.V. Poda, O.G. Polischuk, V.I. Tretyak, Investigation of rare nuclear decays with BaF2 crystal scintillator contaminated by radium, Eur. Phys. J. A 50 (2014) 134

P. Belli, R. Bernabei, R.S. Boiko, F. Cappella, R. Cerulli, F.A. Danevich, A. Incicchitti, B.N. Kropivyansky, M. Laubenstein, D.V. Poda, O.G. Polischuk, V.I. Tretyak, Search for double beta decay of 136Ce and 138Ce with HPGe gamma detector, Nucl. Phys. A 930 (2014) 195.

R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, S. Castellano, R. Cerulli, C.J. Dai, A. d'Angelo, S. d'Angelo, A. Di Marco, H.L. He, A. Incicchitti, H.H. Kuang, X.H. Ma, F. Montecchia, D. Prosperi, X.D. Sheng, R.G. Wang, Z.P. Ye, Final model independent result of DAMA/LIBRA-phase1, Eur. Phys. J. C 73 (2013) 2648.

P. Belli, R. Bernabei, S.V. Budakovsky, F. Cappella, R. Cerulli, F.A. Danevich, S. d'Angelo, A. Incicchitti, M. Laubenstein, D.V. Poda, O.G. Polischuk, V.I. Tretyak, Radioactive contamination of 7LiI(Eu) crystal scintillators, Nucl. Instr. & Meth. A 704 (2013), 40.

F. Cappella, R. Bernabei, P. Belli, V. Caracciolo, R. Cerulli, F.A. Danevich, A. d'Angelo, A. Di Marco, A. Incicchitti, D.V. Poda, V.I. Tretyak, On the potentiality of the ZnWO4 anisotropic detectors to measure the directionality of Dark Matter, Eur. Phys. J. C 73 (2013) 2276.

R. Bernabei, P. Belli, S. d'Angelo, A. Di Marco, F. Montecchia, F. Cappella, A. d'Angelo, A. Incicchitti, V. Caracciolo, S. Castellano, R. Cerulli, C.J. Dai, H.L. He, X.H. Ma, X.D. Sheng, R.G. Wang, Z.P. Ye, Dark Matter investigation by DAMA at Gran Sasso, Int. J. of Mod. Phys. A 28 (2013) 1330022 (73 pages) [arXiv:1306.1411].

P. Belli, R. Bernabei, F. Cappella, R. Cerulli, F.A. Danevich, S. d'Angelo, A. Di Marco, A. Incicchitti, G.P. Kovtun, N.G. Kovtun, M. Laubenstein, D.V. Poda, O.G. Polischuk, A.P. Shcherban, V.I. Tretyak, First search for double-β decay of 184Os and 192Os, Eur. Phys. J. A 49 (2013) 24.

P. Belli, R. Bernabei, F. Cappella, R. Cerulli, F.A. Danevich, S. d'Angelo, A. Incicchitti, G.P. Kovtun, N.G. Kovtun, M. Laubenstein, D.V. Poda, O.G. Polischuk, A.P. Shcherban, D.A. Solopikhn, J. Suhonen, V.I. Tretyak, Search for 2β decays of 96Ru and 104Ru by ultra-low background HPGe spectrometry at LNGS: final results, Phys. Rev. C 87 (2013) 034607. 

R. Bernabei, P. Belli, F. Cappella, V. Caracciolo, S. Castellano, R. Cerulli, C.J. Dai, A. d'Angelo, A. Di Marco, H.L. He, A. Incicchitti, M. Laubenstein, X.H. Ma, F. Montecchia, X.D. Sheng, V.I. Tretyak, R.G. Wang, Z.P. Ye, New search for correlated e+e- pairs in the α decay of 241Am, Eur. Phys. J. A 49 (2013) 64.

R. Bernabei, P. Belli, A. Bussolotti, F. Cappella, V. Caracciolo, M. Casalboni, R. Cerulli, C.J. Dai, A. d'Angelo, A. Di Marco, H.L. He, A. Incicchitti, H.H. Kuang, M. Laubenstein, X.H. Ma, A. Mattei, F. Montecchia, C. Palazzesi, P. Prosposito, X.D. Sheng, R.G. Wang, Z.P. Ye, Performances of the new high quantum efficiency PMTs in DAMA/LIBRA, Journal of Instrumentation 7 (2012) P03009.

P. Belli, R. Bernabei, R.S. Boiko, V.B. Brudanin, F. Cappella, V. Caracciolo, R. Cerulli, D.M. Chernyak, F.A. Danevich, S. d'Angelo, E.N. Galashov, A. Incicchitti, V.V. Kobychev, M. Laubenstein, V.M. Mokina, D.V. Poda, R.B. Podviyanuk, O.G. Polischuk, V.N. Shlegel, Yu.G. Stenin, J. Suhonen, V.I. Tretyak, Ya.V. Vasiliev, Search for double beta decay processes in 106Cd with the help of 106CdWO4 crystal scintillator, Phys. Rev. C 85 (2012) 044610.

 

 

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