75,317 research outputs found

    Associated scalar-vector production at the LHC within an effective Lagrangian approach

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    We consider the case in which a strong dynamics is responsible for Electro-Weak Symmetry Breaking (EWSB) and both a scalar hh and a vector VV, respectively a singlet and a triplet under a custodial SU(2)SU\left(2\right), are relevant and have a mass below the cut-off Λ≈4πv\Lambda\approx 4\pi v. In this framework we study the total cross sections for the associated VhVh production at the LHC at 14 TeV as functions of two independent free parameters.Comment: To appear in the Proceedings of IFAE2010 - Incontri di Fisica delle Alte Energie, Rome, Italy, 7-9 April 201

    Geology and wines of Pachino - Portopalo area : preliminary outlines

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    This research, still in a developmental phase, analyses geological peculiarities and the relation- ships between them and the vineyards typical to the Pachino-Portopalo area. The actual knowledge does not yet allow the drawing of tourist routes from which a geo-tourist would be able to join together Geosites and Oenosites. This will be one of the main topics of future research, oriented to produce substantial contributions to the sustainable development of this area.peer-reviewe

    Channel-based key generation for encrypted body-worn wireless sensor networks

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    Body-worn sensor networks are important for rescue-workers, medical and many other applications. Sensitive data are often transmitted over such a network, motivating the need for encryption. Body-worn sensor networks are deployed in conditions where the wireless communication channel varies dramatically due to fading and shadowing, which is considered a disadvantage for communication. Interestingly, these channel variations can be employed to extract a common encryption key at both sides of the link. Legitimate users share a unique physical channel and the variations thereof provide data series on both sides of the link, with highly correlated values. An eavesdropper, however, does not share this physical channel and cannot extract the same information when intercepting the signals. This paper documents a practical wearable communication system implementing channel-based key generation, including an implementation and a measurement campaign comprising indoor as well as outdoor measurements. The results provide insight into the performance of channel-based key generation in realistic practical conditions. Employing a process known as key reconciliation, error free keys are generated in all tested scenarios. The key-generation system is computationally simple and therefore compatible with the low-power micro controllers and low-data rate transmissions commonly used in wireless sensor networks

    A Deformation Theory of Self-Dual Einstein Spaces

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    The self-dual Einstein equations on a compact Riemannian 4-manifold can be expressed as a quadratic condition on the curvature of an SU(2)SU(2) (spin) connection which is a covariant generalization of the self-dual Yang-Mills equations. Local properties of the moduli space of self-dual Einstein connections are described in the context of an elliptic complex which arises in the linearization of the quadratic equations on the SU(2)SU(2) curvature. In particular, it is shown that the moduli space is discrete when the cosmological constant is positive; when the cosmological constant is negative the moduli space can be a manifold the dimension of which is controlled by the Atiyah-Singer index theorem.Comment: 13 page

    Covariant Phase Space Formulation of Parametrized Field Theories

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    Parametrized field theories, which are generally covariant versions of ordinary field theories, are studied from the point of view of the covariant phase space: the space of solutions of the field equations equipped with a canonical (pre)symplectic structure. Motivated by issues arising in general relativity, we focus on: phase space representations of the spacetime diffeomorphism group, construction of observables, and the relationship between the canonical and covariant phase spaces.Comment: 22 page

    Natural Symmetries of the Yang-Mills Equations

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    We define a natural generalized symmetry of the Yang-Mills equations as an infinitesimal transformation of the Yang-Mills field, built in a local, gauge invariant, and Poincar\'e invariant fashion from the Yang-Mills field strength and its derivatives to any order, which maps solutions of the field equations to other solutions. On the jet bundle of Yang-Mills connections we introduce a spinorial coordinate system that is adapted to the solution subspace defined by the Yang-Mills equations. In terms of this coordinate system the complete classification of natural symmetries is carried out in a straightforward manner. We find that all natural symmetries of the Yang-Mills equations stem from the gauge transformations admitted by the equations.Comment: 23 pages, plain Te

    Schrodinger representation for the polarized Gowdy model

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    The polarized T3{\bf T}^3 Gowdy model is, in a standard gauge, characterized by a point particle degree of freedom and a scalar field degree of freedom obeying a linear field equation on R×S1{\bf R}\times{\bf S}^1. The Fock representation of the scalar field has been well-studied. Here we construct the Schrodinger representation for the scalar field at a fixed value of the Gowdy time in terms of square-integrable functions on a space of distributional fields with a Gaussian probability measure. We show that ``typical'' field configurations are slightly more singular than square-integrable functions on the circle. For each time the corresponding Schrodinger representation is unitarily equivalent to the Fock representation, and hence all the Schrodinger representations are equivalent. However, the failure of unitary implementability of time evolution in this model manifests itself in the mutual singularity of the Gaussian measures at different times.Comment: 13 page
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