17 research outputs found

    Mu2e Crystal Calorimeter Readout Electronics: Design and Characterisation

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    The Mu2e experiment at Fermi National Accelerator Laboratory will search for the charged-lepton flavour-violating neutrinoless conversion of negative muons into electrons in the Coulomb field of an Al nucleus. The conversion electron with a monoenergetic 104.967 MeV signature will be identified by a complementary measurement carried out by a high-resolution tracker and an electromagnetic calorimeter, improving by four orders of magnitude the current single-event sensitivity. The calorimeter—composed of 1348 pure CsI crystals arranged in two annular disks—has a high granularity, 10% energy resolution and 500 ps timing resolution for 100 MeV electrons. The readout, based on large-area UV-extended SiPMs, features a fully custom readout chain, from the analogue front-end electronics to the digitisation boards. The readout electronics design was validated for operation in vacuum and under magnetic fields. An extensive radiation hardness certification campaign certified the FEE design for doses up to 100 krad and 1012 n1MeVeq/cm2 and for single-event effects. A final vertical slice test on the final readout chain was carried out with cosmic rays on a large-scale calorimeter prototype

    Hadronic physics with KLOE

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    The KLOE experiment has collected 2.5 fb−1 of e+e− collisions at the φ peak and about 300 pb−1 in the center-of-mass energy region 1000–1030MeV. Data taken on peak are used to study the properties of light scalar and pseudoscalar mesons, produced through φ radiative decays, and to precisely measure the pion form factor using Initial State Radiation events. Energy scan data are used to measure the cross-section of the process e+e− → ωπ0 as a function of the center-of-mass energy and to perform a preliminary study of the reaction e+e− → e+e−π0π0

    Hadron physics at KLOE and KLOE-2

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    The KLOE experiment at the Frascati ϕ-factory collected large samples of light mesons, providing precise knowledge of their decay dynamics. The η → π+π−γ decay has been studied to search for a possible contribution from chiral anomaly, while a new preliminary high statistics Dalitz plot analysis of the η → π+π−π0 will increase the accuracy of the light quark mass ratio. Pseudoscalar production associated to internal conversion of the photon into a lepton pair allows the measurement of the form factor Fp(q12 = Mϕ2, q22 > 0) in the kinematical region of interest for the VMD model. Detailed study of such decays has been performed both for ϕ → ηe+e− and ϕ → π0e+e− processes. Moreover, data collected at √s have been used to study hadron production in γγ interactions, providing the most precise measurement of the Γ(η → γγ) partial width

    Esclaves et maîtres dans le monde romain

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    La principale distinction relative au droit des personnes est que tous les hommes sont soit libres soit esclaves (Institutes, I, 9). Gaius souligne ainsi la place fondamentale de l’esclavage dans la Rome impériale. La barrière de la liberté était si structurante et le recours au travail servile pratiqué à une telle échelle, que la société romaine mérite assurément le qualificatif d’esclavagiste. Certes, la condition servile était inférieure, mais la concevoir en terme de barrière ou de strate horizontale, séparant les esclaves et les libres, se révèle insuffisant. Dans une population servile à la hiérarchie très marquée, la condition personnelle des esclaves dépendait beaucoup des relations verticales, qui unissaient chacun d’entre eux à leur maître. Tel est le sujet de ce livre collectif. L’examen prioritaire de la documentation épigraphique vise à en restituer la complexité. Il fait place à des serviteurs, à des domesticités et à des maîtres d’une grande diversité, dans différentes régions de l’Empire. Les grandes étapes de la vie des hommes et des femmes réduits en esclavage (l’enfance, la mort, en passant parfois par l’affranchissement) sont prises en compte. C’est aussi dans ses multiples dimensions, du droit aux affects, que la relation entre esclaves et maîtres se trouve mise en lumière

    Calibration and performances of the KLOE calorimeter

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    The KLOE experiment uses a fine sampling lead-scintillating fibrecalorimeter to measure energy, time and position of neutral and charged particles. The overall detector consists of 88 modules organised in a barrel and two end-caps, for a total granularity of 2440 cells, read-out by photo-multipliers at both fibre ends. The chosen design of a high sampling fraction with the usage of thin lead layers and fast scintillating fibres allows to reach good efficiency for photonenergies down to few MeV, good energy resolution and excellent time resolution. The design, calibration and performances of the calorimeter on efficiency, time/position/energy resolution and particle identification is reviewed. The overall calorimeter impact on kaon tagging and on physics results is also presented
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