2,774 research outputs found

    The MGDO software library for data analysis in Ge neutrinoless double-beta decay experiments

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    The GERDA and Majorana experiments will search for neutrinoless double-beta decay of germanium-76 using isotopically enriched high-purity germanium detectors. Although the experiments differ in conceptual design, they share many aspects in common, and in particular will employ similar data analysis techniques. The collaborations are jointly developing a C++ software library, MGDO, which contains a set of data objects and interfaces to encapsulate, store and manage physical quantities of interest, such as waveforms and high-purity germanium detector geometries. These data objects define a common format for persistent data, whether it is generated by Monte Carlo simulations or an experimental apparatus, to reduce code duplication and to ease the exchange of information between detector systems. MGDO also includes general-purpose analysis tools that can be used for the processing of measured or simulated digital signals. The MGDO design is based on the Object-Oriented programming paradigm and is very flexible, allowing for easy extension and customization of the components. The tools provided by the MGDO libraries are used by both GERDA and Majorana.Comment: 4 pages, 1 figure, proceedings for TAUP201

    Методика и методология социолингвистических исследований в условиях билингвизма и диглоссии

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    Lithospheric-scale analogue models are used to analyse the parameters controlling the typical evolution of deformation during continental narrow rifting, characterized by early activation of large boundary faults and basin subsidence, followed by localization of tectonic activity in internal faults at the rift axis. Integration of current and previous experiments shows that the evolution of deformation, in particular the amount of extension needed for the abandonment of boundary faults and migration of deformation to in-rift faults, is dependent on at least five boundary conditions: (i) thickness of brittle layers (including syn-rift sediments); (ii) thickness of ductile layers; (iii) extension rate; (iv) width of the weak zone localizing extension; and (v) rift obliquity with respect to the extension direction. An increase in the amount of extension corresponding to the inward migration of faulting (i.e., a longer phase of slip on boundary faults) is observed for (a) an increase in the thickness of both brittle and ductile crustal layers and syn-rift sediment accumulation, (b) a decrease in extension rate and width of the weak zone, and (c) a decrease in rift obliquity. A unified account of these correlations is presented, based on the hypothesis that fault migration occurs when boundary faults can no longer accommodate the imposed bulk extension, leading to time-space variations of internal strain and strain rate (and consequently stress) in the ductile layers which overcome the total resistance of brittle layers to thoroughgoing faulting

    Bayesian model comparison applied to the Explorer-Nautilus 2001 coincidence data

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    Bayesian reasoning is applied to the data by the ROG Collaboration, in which gravitational wave (g.w.) signals are searched for in a coincidence experiment between Explorer and Nautilus. The use of Bayesian reasoning allows, under well defined hypotheses, even tiny pieces of evidence in favor of each model to be extracted from the data. The combination of the data of several experiments can therefore be performed in an optimal and efficient way. Some models for Galactic sources are considered and, within each model, the experimental result is summarized with the likelihood rescaled to the insensitivity limit value (``R{\cal R} function''). The model comparison result is given in in terms of Bayes factors, which quantify how the ratio of beliefs about two alternative models are modified by the experimental observationComment: 16 pages, 4 figures. Presented at the GWDAW2002 conference, held in Kyoto on Dec.,2002. This version includes comments by the referees of CQG, which has accepted the paper for pubblication in the special issue of the conference. In particular, note that in Eq. 12 there was a typeset error. As suggested by one of the referees, a uniform prior in Log(alpha) has also been considere

    Replica symmetry breaking in mean field spin glasses trough Hamilton-Jacobi technique

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    During the last years, through the combined effort of the insight, coming from physical intuition and computer simulation, and the exploitation of rigorous mathematical methods, the main features of the mean field Sherrington-Kirkpatrick spin glass model have been firmly established. In particular, it has been possible to prove the existence and uniqueness of the infinite volume limit for the free energy, and its Parisi expression, in terms of a variational principle, involving a functional order parameter. Even the expected property of ultrametricity, for the infinite volume states, seems to be near to a complete proof. The main structural feature of this model, and related models, is the deep phenomenon of spontaneous replica symmetry breaking (RSB), discovered by Parisi many years ago. By expanding on our previous work, the aim of this paper is to investigate a general frame, where replica symmetry breaking is embedded in a kind of mechanical scheme of the Hamilton-Jacobi type. Here, the analog of the "time" variable is a parameter characterizing the strength of the interaction, while the "space" variables rule out quantitatively the broken replica symmetry pattern. Starting from the simple cases, where annealing is assumed, or replica symmetry, we build up a progression of dynamical systems, with an increasing number of space variables, which allow to weaken the effect of the potential in the Hamilton-Jacobi equation, as the level of symmetry braking is increased. This new machinery allows to work out mechanically the general K-step RSB solutions, in a different interpretation with respect to the replica trick, and lightens easily their properties as existence or uniqueness.Comment: 24 pages, no figure

    Does Perceptual Belongingness Affect Lightness Constancy?

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    Scientists have shown that two equal grey patches may differ in lightness when belonging to different reflecting surfaces. We extend this investigation to the constancy domain. In a CRT simulation of a bipartite field of illumination, we manipulated the arrangement of twelve patches: six squares and six diamonds. Patches of the same shape could be placed: (i) all within the same illumination field; or (ii) forming a row across the illumination fields. Furthermore, we manipulated proximity between the innermost patches and the illumination edge. The patches could be (i) touching (forming an X-junction); or (ii) not touching (not forming an X-junction). Observers were asked to perform a lightness match between two additional patches, one illuminated and the other in shadow. We found better lightness constancy when the patches of the same shape formed a row across the fields, with no effect of X-junctions

    Mitigation of 42^{42}Ar/42^{42}K background for the GERDA Phase II experiment

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    Background coming from the 42^{42}Ar decay chain is considered to be one of the most relevant for the GERDA experiment, which aims to search of the neutrinoless double beta decay of 76^{76}Ge. The sensitivity strongly relies on the absence of background around the Q-value of the decay. Background coming from 42^{42}K, a progeny of 42^{42}Ar, can contribute to that background via electrons from the continuous spectrum with an endpoint of 3.5 MeV. Research and development on the suppression methods targeting this source of background were performed at the low-background test facility LArGe. It was demonstrated that by reducing 42^{42}K ion collection on the surfaces of the broad energy germanium detectors in combination with pulse shape discrimination techniques and an argon scintillation veto, it is possible to suppress the 42^{42}K background by three orders of magnitude. This is sufficient for Phase II of the GERDA experiment

    The fate of plastic litter within estuarine compartments: an overview of current knowledge for the transboundary issue to guide future assessments

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    Plastics can enter biogeochemical cycles and thus be found in most ecosystems. Most studies emphasize plastic pollution in oceanic ecosystems even though rivers and estuaries are acknowledged as the main sources of plastics to the oceans. This review detected few studies approaching the transboundary issue, as well as patterns of estuarine gradients in predicting plastic distribution and accumulation in water, sediments, and organisms. Quantities of plastics in estuaries reach up to 45,500 items m-3 in water, 567,000 items m-3 in sediment, and 131 items per individual in the biota. The role of rivers and estuaries in the transport of plastics to the ocean is far from fully understood due to small sample sizes, short-term approaches, sampling techniques that underestimate small plastics, and the use of site-specific sampling rather than covering environmental gradients. Microfibres are the most commonly found plastic type in all environmental matrices but efforts to re-calculate pathways using novel sampling techniques and estimates are incipient. Microplastic availability to estuarine organisms and rising/sinking is determined by polymer characteristics and spatio-temporal fluctuations in physicochemical, biological, and mineralogical factors. Key processes governing plastic contamination along estuarine trophic webs remain unclear, as most studies used "species" as an ecological unit rather than trophic/functional guilds and ontogenetic shifts in feeding behaviour to understand communities and intraspecific relationships, respectively. Efforts to understand contamination at the tissue level and the contribution of biofouling organisms as vectors of contaminants onto plastic surfaces are increasing. In conclusion, rivers and estuaries still require attention with regards to accurate sampling and conclusions. Multivariate analysis and robust models are necessary to predict the fate of micro- and macroplastics in estuarine environments; and the inclusion of the socio-economic aspects in modelling techniques seems to be relevant regarding management approaches.FEDER; Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Comparison of relativity theories with observer-independent scales of both velocity and length/mass

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    We consider the two most studied proposals of relativity theories with observer-independent scales of both velocity and length/mass: the one discussed by Amelino-Camelia as illustrative example for the original proposal (gr-qc/0012051) of theories with two relativistic invariants, and an alternative more recently proposed by Magueijo and Smolin (hep-th/0112090). We show that these two relativistic theories are much more closely connected than it would appear on the basis of a naive analysis of their original formulations. In particular, in spite of adopting a rather different formal description of the deformed boost generators, they end up assigning the same dependence of momentum on rapidity, which can be described as the core feature of these relativistic theories. We show that this observation can be used to clarify the concepts of particle mass, particle velocity, and energy-momentum-conservation rules in these theories with two relativistic invariants.Comment: 21 pages, LaTex. v2: Andrea Procaccini (contributing some results from hia Laurea thesis) is added to the list of authors and the paper provides further elements of comparison between DSR1 and DSR2, including the observation that both lead to the same formula for the dependence of momentum on rapidit
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