638 research outputs found

    DAMA/NaI results

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    The DAMA/NaI set-up of the DAMA experiment has been operative during seven annual cycles and has investigated several rare processes. In particular, it has been realised in order to investigate the model independent annual modulation signature for Dark Matter particles in the galactic halo. With the total exposure collected in the seven annual cycles (107731 kg day) a model independent evidence for the presence of a Dark Matter particle component in the galactic halo has been pointed out at 6.3 sigma C.L.. Some of the many possible corollary model dependent quests for the candidate particle have been presented as well.Comment: Contributed paper to the Rencontres de Moriond "Electroweak Interactions and Unified Theories", La Thuile, Aosta Valley, Italy, March 200

    A novel integral representation for the Adler function

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    New integral representations for the Adler D-function and the R-ratio of the electron-positron annihilation into hadrons are derived in the general framework of the analytic approach to QCD. These representations capture the nonperturbative information encoded in the dispersion relation for the D-function, the effects due to the interrelation between spacelike and timelike domains, and the effects due to the nonvanishing pion mass. The latter plays a crucial role in this analysis, forcing the Adler function to vanish in the infrared limit. Within the developed approach the D-function is calculated by employing its perturbative approximation as the only additional input. The obtained result is found to be in reasonable agreement with the experimental prediction for the Adler function in the entire range of momenta 0Q2<0 \le Q^2 < \infty.Comment: 11 pages, 3 figure

    QTLs for Morphogenetic Traits in Medicago Truncatula

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    Plant morphogenesis that includes growth, development and flowering date, drives a large number of agronomical important traits in both grain and forage crops. Quantitative trait locus (QTL) mapping is a way to locate zones of the genome that are involved in the variations observed in a segregating population. Co-location of QTLs and candidate genes is an indication of the involvement of the genes in the variation. The objective of this study was to analyse segregation of aerial morphogenetic traits in a mapping population of recombinant inbred lines of the model legume species M. truncatula , to locate QTLs and candidate genes

    Investigating halo substructures with annual modulation signature

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    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.Comment: 17 pages, 10 figures, to appear in Eur. Phys. J.

    Investigating pseudoscalar and scalar dark matter

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    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

    Investigating electron interacting dark matter

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    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 (χ0\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 correcte

    The DAMA/LIBRA apparatus

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    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 figure
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