160 research outputs found

    The background in the neutrinoless double beta decay experiment GERDA

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    The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay of 76Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the Q-value of the decay, Q_bb. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around Q_bb. The main parameters needed for the neutrinoless double beta decay analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around Q_bb with a background index ranging from 17.6 to 23.8*10^{-3} counts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model are consistent. The observed number of events in this energy region is consistent with the background model. The background at Q-bb is dominated by close sources, mainly due to 42K, 214Bi, 228Th, 60Co and alpha emitting isotopes from the 226Ra decay chain. The individual fractions depend on the assumed locations of the contaminants. It is shown, that after removal of the known gamma peaks, the energy spectrum can be fitted in an energy range of 200 kev around Q_bb with a constant background. This gives a background index consistent with the full model and uncertainties of the same size

    Cтратегии и технологии инновационного развития корпораций

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    У монографії представлено результати дослідження й систематизації теоретичних, науково-методологічних і практичних положень та розробок щодо стратегій та технологій інноваційного розвитку корпорацій. Запропоновано і обґрунтовано технології управління інноваційним розвитком підприємств, стратегії розвитку бізнесу, визначено сучасні реалії та тенденції корпоративного маркетингу, культури та соціальної відповідальності бізнесу, запропоновано нові підходи у корпоративному управлінні, обґрунтовано доцільність використання краудтехнологій фінансування інноваційних проектів, визначено підхо-ди щодо управління персоналом корпорацій в поведінковій економіці. Для науковців та фахівців сфери економіки та управління підприємствам

    Status of the GERDA experiment

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    The study of neutrinoless double beta (0nbb) decay is the only one presently known approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of 0nbb decay would prove that lepton number is not conserved, establish that neutrino has a Majorana component and, assuming that light neutrino is the dominating process, provide a method for the determination of its effective mass. GERDA is a new 0nbb decay experiment which is currently taking data at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. It implements a new shielding concept by operating bare diodes made from Ge with enriched 76Ge in high purity liquid argon supplemented by a water shield. The aim of GERDA is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than past experiments, to increase the sensitive mass and to collect an exposure of 100 kg yr. The paper will discuss design, physics reach, and status of data taking of GERDA.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

    Price assymetry in the Dutch retail gasoline market

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    This paper analyses retail price adjustments in the Dutch gasoline market. We estimate an asymmetric error correction model on weekly price changes for the years 1996 to 2001. We construct five datasets, one for each working day. The conclusions on asymmetric pricing are shown to differ over these datasets, suggesting that the choice of the day for which prices are observed matters more than commonly believed. In our view, the insufficient robustness of outcomes might explain the mixed conclusions found in the literature. Using two approaches, we also show that the effect of asymmetry on Dutch consumer costs is negligible

    The recognition of early developmental stages in haemopoiesis

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    Almost all tissues of multicellular organisms contain cells which have the capacity to change their proliferative activity according to the demand. Some tissues show little or no cellular turnover under normal steady state conditions, but they can switch to a regeneration process in response to perturbation (e.g., mechanical injury). In other tissues, there is continuous cell production to compensate for cell loss due to the continuous utilization of functional cells even under normal conditions. Variation in demand is met by variation in the rate of cell production. The cells which generate offspring throughout life in the continuously renewing tissues are usually designated as stem cells. Stem cells are capable of extensive proliferation which results in new stem cells as well as differentiating cells. The most extensively studied stem cell systems in vertebrates are those of the epidermis, the intestinal epithelium, the testis and the haemopoietic tissues. These systems are commonly used for investigations on the mechanisms of cellular differentiation. In comparison to differentiation processes during embryogenesis, the organization of the stem cell systems in the adult is relatively simple. In adulthood, differentiation is restricted to one or to a limited number of cell types, while, in embryogenesis, differentiation into a large variety of tissues takes plac

    Scaled momentum distributions for K-S(0) and Λ /̄ Λ in DIS at HERA

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    Scaled momentum distributions for the strange hadrons K0S and Λ/Λ¯ were measured in deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 330 pb−1. The evolution of these distributions with the photon virtuality, Q 2, was studied in the kinematic region 10 < Q 2  < 40000 GeV2 and 0.001 < x < 0.75, where x is the Bjorken scaling variable. Clear scaling violations are observed. Predictions based on different approaches to fragmentation were compared to the measurements. Leading-logarithm parton-shower Monte Carlo calculations interfaced to the Lund string fragmentation model describe the data reasonably well in the whole range measured. Next-to-leading-order QCD calculations based on fragmentation functions, FFs, extracted from e + e − data alone, fail to describe the measurements. The calculations based on FFs extracted from a global analysis including e + e −, ep and pp data give an improved description. The measurements presented in this paper have the potential to further constrain the FFs of quarks, anti-quarks and gluons yielding K0S and Λ/Λ¯ strange hadrons

    A QCD analysis of ZEUS diffractive data

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