78 research outputs found

    THE JEM-EUSO MISSION

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    The JEM-EUSO mission explores the origin of the extreme energy cosmic rays (EECRs) above 50EeV and explores the limits of the fundamental physics, through the observations of their arrival directions and energies. It is designed to open a new particle astronomy channel. This superwide-field (60 degrees) telescope with a diameter of about 2.5m looks down from space onto the night sky to detect near UV photons (330 ÷ 400nm, both fluorescent and Cherenkov photons) emitted from the giant air showers produced by EECRs. The arrival direction map with more than five hundred events will tell us the origin of the EECRs and allow us to identify the nearest EECR sources with known astronomical objects. It will allow them to be examined in other astronomical channels. This is likely to lead to an  nderstanding of the acceleration mechanisms perhaps producing discoveries in astrophysics and/or fundamental physics. The comparison of the energy spectra among the spatially resolved individual sources will help to clarify the acceleration/emission mechanism, and also finally confirm the Greisen–Zatsepin–Kuz’min process for the validation of Lorentz invariance up to γ ~ 1011. Neutral components (neutrinos and gamma rays) can also be detected as well, if their fluxes are high enough. The JEM-EUSO mission is planned to be launched by a H2B rocket about 2017 and transferred to ISS by H2 Transfer Vehicle (HTV). It will be attached to the Exposed Facility external experiment platform of “KIBO”

    Deceptive Advertising with Rational Buyers

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    We study a Bertrand game where two sellers supplying products of different and unverifiable qualities can outwit potential clients through their (costly) deceptive advertising. We characterize a class of pooling equilibria where sellers post the same price regardless of their quality and low quality ones deceive buyers. Although in these equilibria low quality goods are purchased with positive probability, the buyer (expected) utility can be higher than in a fully separating equilibrium. It is also argued that low quality sellers invest more in deceptive advertising the better is their reputation vis-à-vis potential clients — i.e., firms that are better trusted by customers, have greater incentives to invest in deceptive advertising when they produce a low quality product. Finally, we characterize the optimal monitoring effort exerted by a regulatory agency who seeks to identify and punish deceptive practices. When the objective of this agency is to maximize consumer surplus, its monitoring effort is larger than under social welfare maximization

    Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

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    JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics

    SN 1987A revisited after 20 years

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    On-line recognition of supernova neutrino burst in LVD

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