321 research outputs found

    ART2 et apprentissage de séquences de mots : l'ordre compte

    No full text
    ISBN : 978-2-9532965-0-1Un réseau Adaptive Resonance Theory a été utilisé pour simuler l'apprentissage des formes orthographiques des mots vus par les enfants. Il a été démontré qu'une modélisation par carte auto-organisatrice permet de rendre compte des performances de l'enfant si on conserve les probabilités d'apparition des mots de la base d'apprentissage. Nous montrons dans cet article avec ART2, que l'ordre d'apparition des mots joue aussi un rôle significatif dans la discrimination des mots plus ou moins orthographiquement voisins. Il en découle une hypothése de construction de corpus favorable é l'apprentissage de la lecture de ce type de mots

    Thomson Scattering of Coherent Diffraction Radiation by an Electron Bunch

    Get PDF
    The paper considers the process of Thomson scattering of coherent diffraction radiation (CDR) produced by the preceding bunch of the accelerator on one of the following bunches. It is shown that the yield of scattered hard photons is proportional to Ne3_e^3, where Ne_e is the number of electrons per bunch. A geometry is chosen for the CDR generation and an expression is obtained for the scattered photon spectrum with regard to the geometry used, that depends in an explicit form on the bunch size. A technique is proposed for measuring the bunch length using scattered radiation characteristics.Comment: 14 pages, LATEX, 6 ps.gz figures, submitted to Phys.Rev.

    All-sky Search for High-Energy Neutrinos from Gravitational Wave Event GW170104 with the ANTARES Neutrino Telescope

    Full text link
    Advanced LIGO detected a significant gravitational wave signal (GW170104) originating from the coalescence of two black holes during the second observation run on January 4th^{\textrm{th}}, 2017. An all-sky high-energy neutrino follow-up search has been made using data from the ANTARES neutrino telescope, including both upgoing and downgoing events in two separate analyses. No neutrino candidates were found within ±500\pm500 s around the GW event time nor any time clustering of events over an extended time window of ±3\pm3 months. The non-detection is used to constrain isotropic-equivalent high-energy neutrino emission from GW170104 to less than ∼4×1054\sim4\times 10^{54} erg for a E−2E^{-2} spectrum

    The ANTARES Collaboration: Contributions to ICRC 2017 Part I: Neutrino astronomy (diffuse fluxes and point sources)

    Get PDF
    Papers on neutrino astronomy (diffuse fluxes and point sources, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio

    The ANTARES Collaboration: Contributions to ICRC 2017 Part III: Searches for dark matter and exotics, neutrino oscillations and detector calibration

    Get PDF
    Papers on the searches for dark matter and exotics, neutrino oscillations and detector calibration, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio

    The ANTARES Collaboration: Contributions to ICRC 2017 Part II: The multi-messenger program

    Get PDF
    Papers on the ANTARES multi-messenger program, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboratio

    The Antares Collaboration : Contributions to the 34th International Cosmic Ray Conference (ICRC 2015, The Hague)

    Get PDF
    The ANTARES detector, completed in 2008, is the largest neutrino telescope in the Northern hemisphere. Located at a depth of 2.5 km in the Mediterranean Sea, 40 km off the Toulon shore, its main goal is the search for astrophysical high energy neutrinos. In this paper we collect the 21 contributions of the ANTARES collaboration to the 34th International Cosmic Ray Conference (ICRC 2015). The scientific output is very rich and the contributions included in these proceedings cover the main physics results, ranging from steady point sources, diffuse searches, multi-messenger analyses to exotic physics

    Limits on the nuclearite flux using the ANTARES neutrino telescope

    Full text link
    In this work, a search for nuclearites of strange quark matter by using nine years of ANTARES data taken in the period 2009-2017 is presented. The passage through matter of these particles is simulated %according to the model of de R\'{u}jula and Glashow taking into account a detailed description of the detector response to nuclearites and of the data acquisition conditions. A down-going flux of cosmic nuclearites with Galactic velocities (β=10−3\beta = 10^{-3}) was considered for this study. The mass threshold for detecting these particles at the detector level is \mbox{ 4×10134 \times 10^{13} GeV/c2^{2}}. Upper limits on the nuclearite flux for masses up to 101710^{17} GeV/c2^{2} at the level of ∼5×10−17\sim 5 \times 10^{-17} cm−2^{-2} s−1^{-1} sr−1^{-1} are obtained. These are the first upper limits on nuclearites established with a neutrino telescope and the most stringent ever set for Galactic velocities.Comment: 17 pages, 7 figure

    ANTARES search for point-sources of neutrinos using astrophysical catalogs: a likelihood stacking analysis

    Full text link
    A search for astrophysical point-like neutrino sources using the data collected by the ANTARES detector between January 29, 2007 and December 31, 2017 is presented. A likelihood stacking method is used to assess the significance of an excess of muon neutrinos inducing track-like events in correlation with the location of a list of possible sources. Different sets of objects are tested in the analysis: a) a sub-sample of the \textit{Fermi} 3LAC catalog of blazars, b) a jet-obscured AGN population, c) a sample of soft gamma-ray selected radio galaxies, d) a star-forming galaxy catalog , and e) a public sample of 56 very-high-energy track events from the IceCube experiment. None of the tested sources shows a significant association with the sample of neutrinos detected by ANTARES. The smallest p-value is obtained for the radio galaxies catalog with an equal weights hypothesis, with a pre-trial p-value equivalent to a 2.8 σ2.8 \, \sigma excess, equivalent to 1.6 σ1.6 \, \sigma post-trial. In addition, the results of a dedicated analysis for the blazar MG3 J225517+2409 are also reported: this source is found to be the most significant within the \textit{Fermi} 3LAC sample, with 5 ANTARES events located at less than one degree from the source. This blazar showed evidence of flaring activity in \textit{Fermi} data, in space-time coincidence with a high-energy track detected by IceCube. An \emph{a posteriori} significance of 2.0 σ2.0\, \sigma for the combination of ANTARES and IceCube data is reported
    • …
    corecore