38,351 research outputs found

    Field dependence of the switching field for nonellipsoidal single domain particles

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    Experimental data on a model system of a two-dimensional array of single domain garnet particles, switching by incoherent rotation, are presented to show that the switching field of individual particles, H-sw, and the coercivity of the major hysteresis loop for similar to1000 particles, H-c, depend on the previously applied saturating field. For the system measured the asymptotic, "true" value of H-c in large fields is 321 Oe, in contrast with H-c=225 Oe, measured in an applied field of H-sat=188 Oe, i.e., the smallest field adequate to close the major loop. Statistical data were collected on switching of a single particle, with an asymptotic value of H-sw=150 Oe. After the application of H-sat=160 Oe H-sw decreased to 111 Oe. Due to the nonellipsoidal shape of the particles, a significant canting of the magnetization near corners and edges persists up to very high fields. The torque, due to these canted magnetic moments, facilitates premature switching in lower fields. It is proposed that defects are responsible for the irreversibility of the process

    Cultural value perception in the memorable tourism experience

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    Tourism management curriculum, if its ultimate objective is to give an introduction to the modern trends in tourism management and marketing and to prepare future destination managers, must inevitably incorporate – together with all their theoretical and practical implications - the phenomena of experiential consumption and value co-creation

    Search for the Higgs Boson: a Statistical Adventure of Exclusion and Discovery

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    The 40 years old Standard Model, the theory of particle physics, seems to describe all experimental data very well. All of its elementary particles were identified and studied apart from the Higgs boson until 2012. For decades many experiments were built and operated searching for it, and finally, the two main experiments of the Large Hadron Collider at CERN, CMS and ATLAS, in 2012 observed a new particle with properties close to those predicted for the Higgs boson. In this talk we describe the search process: the exclusion of the Higgs boson at LEP, the Large Electron Positron collider, and the observation at LHC of a new boson with properties close to those predicted for the Higgs boson of the Standard Model. We try to pay special attention on the statistical methods used.Comment: Plenary invited lecture at CCP-2013: XXV IUPAP Conference on Computational Physics, Landau Institute for Theoretical Physics, Moscow, Russia, 21 August 201

    Low-dimensional long-range topological structure in the QCD vacuum

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    Lattice topological charge associated with Ginsparg-Wilson fermions exhibits generic topological stability over quantum ensemble of configurations contributing to the QCD path integral. Moreover, the underlying chiral symmetry leads to the suppression of ultraviolet noise in the associated topological charge densities ("chiral smoothing"). This provides a solid foundation for the direct study of the role of topological charge fluctuations in the physics of QCD vacuum. Using these tools it was recently demonstrated that: (a) there is a well-defined space-time structure (order) in topological charge density (defined through overlap fermions) for typical configurations contributing to QCD path integral; (b) this fundamental structure is low-dimensional, exhibiting sign-coherent behavior on subsets of dimension less than four and not less than one; (c) the structure has a long-range global character (spreading over maximal space-time distances) and is built around the locally one-dimensional network of strong fields (skeleton). In this talk we elaborate on certain aspects and implications of these results.Comment: 3 pages, 1 figure; Lattice2003(topology

    Classification of BeppoSAX's Gamma-Ray Bursts

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    The BeppoSAX Catalog has been very recently published. In this paper we analyze - using the Maximum Likelihood (ML) method - the duration distribution of the 1003 GRBs listed in the catalog with duration. The ML method can identify the long and the intermediate duration groups. The short population of the bursts is identified only at a 96% significance level. MC simulation has been also applied and gives a similar significance level; 95%. However, the existence of the short bursts is not a scientific question after the Compton Gamma-Ray Observatory's observation. Our minor result is this well-known fact that in the BeppoSAX data the short bursts are underrepresented, mainly caused by the different triggering system. Our major result is the identification of the intermediate group in the BeppoSAX data. Therefore, four different satellites (CGRO, Swift, RHESSI and BeppoSAX) observed the intermediate type Gamma-Ray Burst.Comment: Accepted for publication in Astrophysics & Space Scienc
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