1,409 research outputs found

    The Topological Non-connectivity Threshold in quantum long-range interacting spin systems

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    Quantum characteristics of the Topological Non-connectivity Threshold (TNT), introduced in F.Borgonovi, G.L.Celardo, M.Maianti, E.Pedersoli, J. Stat. Phys., 116, 516 (2004), have been analyzed in the hard quantum regime. New interesting perspectives in term of the possibility to study the intriguing quantum-classical transition through Macroscopic Quantum Tunneling have been addressed.Comment: contribution to NEXTSIGMAPHI 3r

    Performance of a large limited streamer tube cell in drift mode

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    The performance of a large (3x3 cm2cm^2) streamer tube cell in drift mode is shown. The detector space resolution has been studied using cosmic muons crossing an high precision silicon telescope. The experimental results are compared with a GARFIELD simulation.Comment: 18 pages, 7 figures. Accepted by Nucl. Instr. and Methods

    High energy extension of the FLUKA atmospheric neutrino flux

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    The atmospheric neutrino flux calculated with FLUKA was originally limited to 100-200 GeV for statistical reasons. In order to make it available for the analysis of high energy events, like upward through-going muons detected by neutrino telescopes, we have extended the calculation so to provide a reliable neutrino yield per primary nucleon up to about 10**6 GeV/nucleon, as far as the interaction model is concerned. We point out that the primary flux model above 100 GeV/nucleon still contributes with an important systematic error to the neutrino flux.Comment: Extended version (10 pages) of the contribution to ICRC 2003, with the addition of flux table

    The hadronic models for cosmic ray physics: the FLUKA code solutions

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    FLUKA is a general purpose Monte Carlo transport and interaction code used for fundamental physics and for a wide range of applications. These include Cosmic Ray Physics (muons, neutrinos, EAS, underground physics), both for basic research and applied studies in space and atmospheric flight dosimetry and radiation damage. A review of the hadronic models available in FLUKA and relevant for the description of cosmic ray air showers is presented in this paper. Recent updates concerning these models are discussed. The FLUKA capabilities in the simulation of the formation and propagation of EM and hadronic showers in the Earth's atmosphere are shown.Comment: 8 pages, 9 figures. Invited talk presented by M.V. Garzelli at ISVHECRI2006, International Symposium on Very High Energy Cosmic Rays, Weihai, China, August 15 - 22 200

    Atmospheric neutrinos in a Large Liquid Argon detector

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    In view of the evaluation of the physics goals of a large Liquid Argon TPC, evolving from the ICARUS technology, we have studied the possibility of performing precision measurements on atmospheric neutrinos. For this purpose we have improved existing Monte Carlo neutrino event generators based on FLUKA and NUX by including the 3-flavor oscillation formalism and the numerical treatment of Earth matter effects. By means of these tools we have studied the sensitivity in the measurement of Theta(23) through the accurate measurement of electron neutrinos. The updated values for Delta m^2(23) from Super-Kamiokande and the mixing parameters as obtained by solar and KamLand experiments have been used as reference input, while different values of Theta(13) have been considered. An exposure larger than 500 kton yr seems necessary in order to achieve a significant result, provided that the present knowledge of systematic uncertainties is largely improved.Comment: Talk given at the worksgop "Cryogenic Liquid Detectors for Future Particle Physics", LNGS (Italy) March 13th-14th, 200

    The FLUKA Monte Carlo, non-perturbative QCD and Cosmic Ray cascades

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    The FLUKA Monte Carlo code, presently used in cosmic ray physics, contains packages to sample soft hadronic processes which are built according to the Dual Parton Model. This is a phenomenological model capable of reproducing many of the features of hadronic collisions in the non perturbative QCD regime. The basic principles of the model are summarized and, as an example, the associated Lambda-K production is discussed. This is a process which has some relevance for the calculation of atmospheric neutrino fluxes.Comment: Extended version of the work for the proceedings of the workshop on QCD at Cosmic Ray Energies, Erice, Aug. 30 - Sep. 4 2004, Ital

    A. Season of Service: Introducing Service Learning into the Liberal Arts Curriculum

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    We live in times when rights and obligations have become uncoupled. Individuals regard themselves almost exclusively as private persons with responsibilities only to family and job and yet possessing endless rights against a distant and alien state in relationship to which they think or themselves, at best, as watchdogs and clients and, at worst, as adversaries and victims. The idea of service to country or to the institutions by which rights and liberty are legitimized and sustained has fairly vanished

    Dethinning Extensive Air Shower Simulations

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    We describe a method for restoring information lost during statistical thinning in extensive air shower simulations. By converting weighted particles from thinned simulations to swarms of particles with similar characteristics, we obtain a result that is essentially identical to the thinned shower, and which is very similar to non-thinned simulations of showers. We call this method dethinning. Using non-thinned showers on a large scale is impossible because of unrealistic CPU time requirements, but with thinned showers that have been dethinned, it is possible to carry out large-scale simulation studies of the detector response for ultra-high energy cosmic ray surface arrays. The dethinning method is described in detail and comparisons are presented with parent thinned showers and with non-thinned showers

    HyBIS: Windows Guest Protection through Advanced Memory Introspection

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    Effectively protecting the Windows OS is a challenging task, since most implementation details are not publicly known. Windows has always been the main target of malwares that have exploited numerous bugs and vulnerabilities. Recent trusted boot and additional integrity checks have rendered the Windows OS less vulnerable to kernel-level rootkits. Nevertheless, guest Windows Virtual Machines are becoming an increasingly interesting attack target. In this work we introduce and analyze a novel Hypervisor-Based Introspection System (HyBIS) we developed for protecting Windows OSes from malware and rootkits. The HyBIS architecture is motivated and detailed, while targeted experimental results show its effectiveness. Comparison with related work highlights main HyBIS advantages such as: effective semantic introspection, support for 64-bit architectures and for latest Windows (8.x and 10), advanced malware disabling capabilities. We believe the research effort reported here will pave the way to further advances in the security of Windows OSes
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