5,442 research outputs found

    Initial Conditions for Large Cosmological Simulations

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    This technical paper describes a software package that was designed to produce initial conditions for large cosmological simulations in the context of the Horizon collaboration. These tools generalize E. Bertschinger's Grafic1 software to distributed parallel architectures and offer a flexible alternative to the Grafic2 software for ``zoom'' initial conditions, at the price of large cumulated cpu and memory usage. The codes have been validated up to resolutions of 4096^3 and were used to generate the initial conditions of large hydrodynamical and dark matter simulations. They also provide means to generate constrained realisations for the purpose of generating initial conditions compatible with, e.g. the local group, or the SDSS catalog.Comment: 12 pages, 11 figures, submitted to ApJ

    Search for Bs0sB^{0}_{s}s oscillations using inclusive lepton events

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    A new search for Bs oscillations is performed in a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the proper time resolution and mistag are significantly improved. In addition sub-samples of the data are assigned an enriched or depleted Bs fraction. Maximum likelihood fits are performed to derive a preliminary lower limit of Dms > 10.2 ps-1 at 95L. Combining with the ALEPH Ds based analyses yields Dms>10.4 ps-1 at 95L

    WIRELESS AND BATTERYLESS SURFACE ACOUSTIC WAVE SENSORS FOR HIGH TEMPERATURE ENVIRONMENTS

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    International audienceSurface acoustic wave (SAW) devices are widely used as filter, resonator or delay line in electronic systems in a wide range of applications: mobile communication, TVs, radar, stable resonator for clock generation, etc. The resonance frequency and the delay line of SAW devices are depending on the properties of materials forming the device and could be very sensitive to the physical parameters of the environment. Since SAW devices are more and more used as sensor for a large variety of area: gas, pressure, force, temperature, strain, radiation, etc. The sensors based SAW present the advantage to be passive (batteryless) and/or wireless. These interesting properties combined with a small size, a low cost radio request system and a small antennas when operating at high frequency, offer new and exiting perspectives for wireless measurement processes and IDTAG applications. When the materials constituting the devices are properly selected, it becomes possible to use those sensors without embedded electronic in hostile environments (as high temperature, nuclear site, …) where no solutions are currently used. General principle of the SAW sensor in wired and wireless configurations will be developed and a review of recent works concerning the field of high temperature applications will be presented with specific attention given to the choice of materials constituting the SAW device

    Massive Stars in the Range 1325M\rm 13-25 M_\odot: Evolution and Nucleosynthesis. II. the Solar Metallicity Models

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    We present the evolutionary properties of a set of massive stellar models (namely 13, 15, 20 and 25 M\rm M_\odot) from the main sequence phase up to the onset of the iron core collapse. All these models have initial solar chemical composition, i.e. Y=0.285 and Z=0.02. A 179 isotope network, extending from neutron up to 68Zn\rm ^{68}Zn and fully coupled to the evolutionary code has been adopted from the Carbon burning onward. Our results are compared, whenever possible, to similar computations available in literature.Comment: 42 pages, 18 figures, 26 tables, accepted for publicatin in ApJ

    Many-body theory interpretation of deep inelastic scattering

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    We analyze data on deep inelastic scattering of electrons from the proton using ideas from standard many-body theory involving {\em bound} constituents subject to {\em interactions}. This leads us to expect, at large three-momentum transfer q{\bf{q}}, scaling in terms of the variable y~=νq\tilde{y}=\nu-{\bf |q|}. The response at constant q{\bf |q|} scales well in this variable. Interaction effects are manifestly displayed in this approach. They are illustrated in two examples.Comment: 10 pages, 4 figure

    Suppressed decay into open charm for the Y(4260) being an hybrid

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    We investigate the Y(4260) resonance recently discovered by the Babar collaboration. We propose the observation of its decay into J/psi pi pi and its non observation into open charm as a consequence of it being a charmonium hybrid state with a magnetic constituent gluon. We prove a selection rule forbidding its decay into two S-wave charmed mesons in any potential model. We suggest a generalisation of the selection rule based only on the heavy quark nature of the charm.Comment: 5 page

    Q**2-dependence of deep inelastic lepton scattering off nuclear targets

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    Deep inelastic scattering of leptons off nuclear targets is analized within the convolution model taking into account nucleon-nucleon correlations. We show that in the nuclear medium nucleons are distributed according to a function that exhibits a sizeable Q**2-dependence and reduces to the ordinary light-cone distribution in the Bjorken limit. At Q**2 1 this Q**2-dependence turns out to be stronger than the one associated with the nucleon structure function, predicted by pertubative quantum chromodynamics.Comment: 11 pages including figs. Figs. can be sent by PS-fil

    Two charged strangeonium-like structures observable in the Y(2175)ϕ(1020)π+πY(2175) \to \phi(1020)\pi^{+} \pi^{-} process

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    Via the Initial Single Pion Emission (ISPE) mechanism, we study the ϕ(1020)π+\phi(1020)\pi^{+} invariant mass spectrum distribution of Y(2175)ϕ(1020)π+πY(2175) \to \phi(1020)\pi^{+} \pi^{-}. Our calculation indicates there exist a sharp peak structure (Zs1+Z_{s1}^+) close to the KKˉK\bar{K}^\ast threshold and a broad structure (Zs2+Z_{s2}^+) near the KKˉK^\ast\bar{K}^\ast threshold. In addition, we also investigate the ϕ(1680)ϕ(1020)π+π\phi(1680) \to \phi(1020)\pi^{+} \pi^{-} process due to the ISPE mechanism, where a sharp peak around the KKˉK\bar{K}^\ast threshold appears in the ϕ(1020)π+\phi(1020)\pi^{+} invariant mass spectrum distribution. We suggest to carry out the search for these charged strangeonium-like structures in future experiment, especially Belle II, Super-B and BESIII.Comment: 7 pages, 5 figures. Accepted by Eur. Phys. J.
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