1,720,990 research outputs found
Possible implications of the channeling effect in NaI(Tl) crystals
No full textThe 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
Dark matter signals: from underground to space investigations
No full textThe DAMA/NaI experiment (similar or equal to 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 x day, collected over seven annual cycles, it has pointed out at 6.3 sigma 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 (similar or equal to 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
Investigation on light dark matter
No full textSome 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. © 2008 World Scientific Publishing Company
Search for double beta decay processes in 108Cd and 114Cd with the help of low background CdWO4 crystal scintillator
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Particle dark matter: From DAMA/NaI to DAMA/LIBRA
No full textDAMA is an observatory for rare processes and 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/Nal setup (similar or equal to 100 kg of highly radiopure NaI(Tl)) has effectively investigated the model-independent annual modulation signature over seven annual cycles (total exposure of 107 731 kg day), obtaining 6.3 sigma 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 been investigated and others are in progress. At present, the second generation DAMA/LIBRA setup (similar or equal to 250 kg of highly radiopure NaI(T1)) is in data taking deep underground
Investigating pseudoscalar and scalar Dark Matter
No full textIn 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 setup. 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
Prospects for DAMA/LIBRA and beyond
No full textAs a result of about five years of new developments, the second-generation LIBRA (Large sodium Iodide Bulk for RAre processes) set-up of the DAMA experiment has been realized and installed in the Gran Sasso National Laboratory of the I.N.F.N.. It is made of ≃250 kg low-background NaI(Tl) detectors and has been operative since March 2003. It works as an observatory for rare processes and is mainly devoted to further investigation on the dark matter particle component in the galactic halo. New R&D efforts toward a possible NaI(Tl) ton set-up, which we proposed in 1996, have been funded and started in 2003. © 2004 Elsevier B.V. All rights reserved
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