2,433 research outputs found

    A linear moose model with pairs of degenerate gauge boson triplets

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    The possibility of the existence of a strongly interacting electroweak symmetry breaking sector, as opposed to the weakly interacting light Higgs of the Standard Model, is not yet ruled out by experiments. In this paper we make an extensive study of a deconstructed model (or ``moose'' model) providing a possible effective description of such a strong symmetry breaking sector, and show its compatibility with experimental data for a wide portion of the model parameters space. The model is a direct generalization of the previously proposed D-BESS model.Comment: Latex file, 17 pages, 2 figures, published versio

    The Invisible Higgs Decay Width in the Add Model at the LHC

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    Assuming flat universal extra dimensions, we demonstrate that for a light Higgs boson the process pp→W∗W∗+X→Higgs,graviscalars+X→invisible+Xpp\to W^*W^* +X \to Higgs,graviscalars +X \to invisible+X will be observable at the 5σ5 \sigma level at the LHC for the portion of the Higgs-graviscalar mixing (Ο\xi) and effective Planck mass (MDM_D) parameter space where channels relying on visible Higgs decays fail to achieve a 5σ5 \sigma signal. Further, we show that even for very modest values of Ο\xi the invisible decay signal probes to higher MDM_D than does the (Ο\xi-independent) jets/\gam + missing energy signal from graviton radiation. We also discuss various effects, such as Higgs decay to two graviscalars, that could become important when mh/MDm_h/M_D is of order 1.Comment: 6 pages, 2 figures, To appear in the Proceedings of the Les Houches Workshop 2003: ``Physics at TeV Colliders'', ed. F. Boudjem

    Limits and Criticalities of Predictions and Forecasting in Complex Social and Economic Scenarios: A Cybernetics Key

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    Predictions play a key role in assuring the status of “rationality” in decisions. Nevertheless, in the ïŹeld of social sciences and economics, predictions fail to correctly depict the oncoming scenarios. Why is it so difïŹcult to achieve quantitative prediction of social and economic systems? Can science provide reliable predictions of social and economic paths that can be used to implement effective interventions? As in the notorious “El Farol bar problem” depicted by Brian Arthur (Am Econ Rev 84:406–411, 1994), the validity of predictive models is more a social issue than a matter of good mathematics. Predictability in social systems is due to limited knowledge of society and human behavior. We do not yet have worldwide, quantitative knowledge of human social behavior; for instance, the perception of certain issues or the predisposition to adopt certain behaviors. Though tremendous progress has been made in recent years in data gathering thanks to the development of new technologies and the consequent increase in computational power, social and economic models still rely on assumptions of rationality that undermine their predictive effectiveness. Through some theoretical and epistemological reïŹ‚ections, we propose a way in which the cybernetic paradigm of complexity management can be used for better decision-making in complex scenarios with a comprising, dynamic, and evolving approach. We will show how a cybernetic approach can help to overcome the fear of uncertainty and serve as an effective tool for improving decisions and actions

    University Incubator as Catalyst of Resources for Academic Spin-Offs. The Case of ARCA Consortium

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    Today we can observe an increasing proliferation of new academic spin-off initiatives aimed to transfer knowledge from the university to the market. Due to their strategic role in enhancing the development of technological innovation, academic spin-offs can attain high levels of social performance and consonance with their environment. At the same time, they must overcome many difficulties if they are to achieve a high level of financial performance and growth. They are often considered to be mere vehicles for the transmission of knowledge, implying that their entrepreneurial potential is not fully exploited. According to the Resource Based View (RBV) the competitive disadvantage of an academic spin-off is due to a lack of resources. This paper will join this stream of research in order to analyze the financial performance of academic spin-offs. We examine the case of Arca Consortium’s incubator, established by the University of Palermo, and of the academic spin-offs it has supported and continues to assist. The empirical analysis, based on two linear regression models, is performed based on 19 case studies of spin-offs created between 2007 and 2009 by academicians of the University of Palerm

    The Drivers of Customer Satisfaction in the Hospitality Industry. Applying the Kano Model to Sicilian Hotels

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    Starting from the assessment that hotels need to embrace a managerial approach oriented towards customer satisfaction, we adopt the Kano model to identify the relevant drivers of satisfaction of hotels guest in the main cities of Sicily, Italy. This study analyzes the customer satisfaction requirements for Sicilian hotels in order to suggest and weigh a set of key attributes that hotel managers need to consider in order to create an attractive offer. We base our analysis on the qualitative data collected through 600 questionnaires submitted to hotel guests of twenty Sicilian three-star hotels located in city downtowns, in different provinces and locations

    Evidence of microbial activity from a shallow water whale fall (Voghera, northern Italy)

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    The fossil bones, associated carbonate cements and enclosing concretion of a Miocene mysticete from inner shelf deposits (Monte Vallassa Formation, northern Italy) were analyzed for evidence of microbial activity. Optical and scanning electron microscopy, Raman spectroscopy, and stable C and O isotope geochemistry were used for high spatial resolution microfacies and biosedimentological analyses. Whale cancellous bones were filled by different carbonate cements including microcrystalline dolomite, rhombohedral dolomite and sparry calcite. Biofabric and biominerals such as microbial peloids, clotted textures and pyrite framboids were associated with the dolomite cements. Dolomite inside cancellous bones and in the enclosing concretion showed similar isotopic values (avg ÎŽ 13C: -7.12‰; avg ÎŽ 18O: +3.81‰), depleted with respect to the (late) sparry calcite cement (avg ÎŽ 13C: -0.55‰; avg ÎŽ 18O: -0.98‰). Microcrystalline barite (BaSO 4) was observed on the external surface of the bones. In addition, two different types of microborings were recognized, distinguished by their size and morphology and were ascribed respectively to prokaryote and fungal trace makers. Our results testify for the development of a diverse microbial ecosystem during the decay of a shallow water whale carcass, which could be detected in the fossil record. However, none of the observed biosignatures (e.g., microbial peloids, clotted textures) can be used alone as a positive fossil evidence of the general development of a sulfophilic stage of whale fall ecological succession. The occurrence of the hard parts of chemosynthetic invertebrates associated with fossil whale bones is still the more convincing proof of the development of a sulfide-base chemoautotrophic ecosystem. © 2011 Elsevier B.V

    Saving the fourth generation Higgs with radion mixing

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    We study Higgs-radion mixing in a warped extra dimensional model with Standard Model fields in the bulk, and we include a fourth generation of chiral fermions. The main problem with the fourth generation is that, in the absence of Higgs-radion mixing, it produces a large enhancement in the Higgs production cross-section, now severely constrained by LHC data. We analyze the production and decay rates of the two physical states emerging from the mixing and confront them with present LHC data. We show that the current signals observed can be compatible with the presence of one, or both, of these Higgs-radion mixed states (the ϕ\phi and the hh), although with a severely restricted parameter space. In particular, the radion interaction scale must be quite low, Lambda_\phi ~ 1-1.3 TeV. If m_\phi ~ 125 GeV, the hh state must be heavier (m_h>320 GeV). If m_h ~ 125 GeV, the ϕ\phi state must be quite light or close in mass (m_\phi ~ 120 GeV). We also present the modified decay branching ratios of the mixed Higgs-radion states, including flavor violating decays into fourth generation quarks and leptons. The windows of allowed parameter space obtained are very sensitive to the increased precision of upcoming LHC data. During the present year, a clear picture of this scenario will emerge, either confirming or further severely constraining this scenario.Comment: 22 pages, 5 figures, 4 table

    Analysis of Narrow s-channel Resonances at Lepton Colliders

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    The procedures for studying a single narrow s-channel resonance or nearly degenerate resonances at a lepton collider, especially a muon collider, are discussed. In particular, we examine four methods for determining the parameters of a narrow s-channel resonance: scanning the resonance, measuring the convoluted cross section, measuring the Breit-Wigner area, and sitting on the resonance while varying the beam energy resolution. This latter procedure is new and appears to be potentially very powerful. Our focus is on computing the errors in resonance parameters resulting from uncertainty in the beam energy spread. Means for minimizing these errors are discussed. The discussion is applied to the examples of a light SM-Higgs, of the lightest pseudogoldstone boson of strong electroweak breaking, and of the two spin-1 resonances of the Degenerate BESS model (assuming that the beam energy spread is less than their mass splitting). We also examine the most effective procedures for nearly degenerate resonances, and apply these to the case of Degenerate BESS resonances with mass splitting of order the beam energy spread.Comment: 63 pages, 16 figure

    A Strong Electroweak Sector at Future mu^+ mu^- Colliders

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    We discuss the prospects for detecting at a muon collider the massive new vector resonances V and light pseudo-Nambu-Goldstone bosons P of a typical strongly interacting electroweak sector (as represented by the BESS model). Expected sensitivities to V's at a high energy collider are evaluated and the excellent prospects for discovering P's via scanning at a low energy collider are delineated.Comment: LaTeX, uses aipproc.cls, aipproc.sty, 10 pages, 6 figures, presented at the Workshop on Physics at the First Muon Collider, Fermilab, November 1997, to appear in the Proceedings, some references added and minor changes in the tex
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