2,213 research outputs found

    TOTEM: The experiment to measure the total proton-proton cross section at LHC

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    The current large uncertainty on the extrapolation of the proton-proton total cross section at the LHC energy will be resolved by the precise measurement by the TOTEM experiment. Its accurate studies on the basic properties of proton-proton collisions at the maximum accelerator energy could provide a significant contribution to the understanding of cosmic ray physics.Comment: 6 pages, 7 figures, Proceedings XIV International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2006), Weihai, China, August 15-22, 200

    KπK \to \pi semileptonic form factors with Nf=2+1+1N_f=2+1+1 Twisted Mass fermions

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    We present a lattice QCD determination of the vector and scalar form factors of the semileptonic KπνK \to \pi \ell \nu decay which are relevant for the extraction of the CKM matrix element Vus|V_{us}| from experimental data. Our results are based on the gauge configurations produced by the European Twisted Mass Collaboration with Nf=2+1+1N_f = 2+1+1 dynamical fermions, which include in the sea, besides two light mass degenerate quarks, also the strange and the charm quarks. We use data simulated at three different values of the lattice spacing and with pion masses as small as 210210 MeV. Our final result for the vector form factor at zero momentum transfer is f+(0)=0.9709(46)f_+(0) = 0.9709 (46), where the uncertainty is both statistical and systematic combined in quadrature. Using the latest experimental value of f+(0)Vusf_+(0) |V_{us}| from K3K_{\ell 3} decays, we obtain Vus=0.2230(11)|V_{us}| = 0.2230 (11), which allows to test the unitarity constraint of the Standard Model below the permille level once the determination of Vud|V_{ud}| from superallowed nuclear β\beta decays is adopted. A slight tension with unitarity at the level of 2\sim 2 standard deviations is observed. Moreover we present our results for the semileptonic scalar f0(q2)f_0(q^2) and vector f+(q2)f_+(q^2) form factors in the whole range of values of the squared four-momentum transfer q2q^2 measured in K3K_{\ell 3} decays, obtaining a very good agreement with the momentum dependence of the experimental data. We provide a set of synthetic data points representing our results for the vector and scalar form factors at the physical point for several selected values of q2q^2.Comment: 37 pages, 5 tables, 9 figures; version to appear in PR

    A triple-GEM telescope for the TOTEM experiment

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    The TOTEM experiment at LHC has chosen the triple Gas Electron Multiplier (GEM) technology for its T2 telescope which will provide charged track reconstruction in the rapidity range 5.3<|eta|<6.5 and a fully inclusive trigger for diffractive events. GEMs are gas-filled detectors that have the advantageous decoupling of the charge amplification structure from the charge collection and readout structure. Furthermore, they combine good spatial resolution with very high rate capability and a good resistance to radiation. Results from a detailed T2 GEM simulation and from laboratory tests on a final design detector performed at CERN are presented.Comment: To appear in the proceedings of 10th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD06), Siena, Italy, October 1-5 200

    The CDF MiniPlug Calorimeters at the Tevatron

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    Two MiniPlug calorimeters, designed to measure the energy and lateral position of particles in the pseudorapidity region of 3.6<|eta|<5.1 of the CDF detector, have been installed as part of the Run II CDF upgrade at the Tevatron collider. Detector performance and first results from pˉp\bar pp collision data are presented.Comment: Presented at `Frontier Detectors for Frontier Physics; 9th Pisa Meeting on Advanced Detectors', Biodola, Italy, 25-31 May 2003. 2 page

    New Limited Molecular Weight Polymeric Dispersants Prepared by Melt Condensation Polymerization

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    In this work, poly(sebacic anhydride) was prepared in a new method of condensation polymerization of sebacic acid monomer and sebacoyl chloride monomer in presence of triethyl amine, this polymer was purified, characterized by infrared spectroscopy. Poly(sebacic anhydride) was used to prepare poly(ethylene glycol)-sebacic acid copolymers with carboxylic end groups and limited molecular weight using poly(ethylene glycol) having different chain length (400, 2000, 10000 and 20000 g/mole) by melt condensation polymerization. The copolymers were purified, characterized by infrared spectroscopy and end-group analysis of molecular weight determination technique. These polymers were tested as dispersants for ceramic alumina particles in ethanol as dispersion medium using centrifugation settlement method; High packing densities for alumina particles were obtained. It was found that the packing densities of alumina particles have been influenced by the polymer concentration and poly) ethylene glycol) chain length. Their adsorption isotherms were also determined, it was found that the adsorption is molecular weight dependent and linear relationship was obtained between the maximum adsorption of the polymers and their molecular weights. Keywords: melt condensation, poly(sebacic anhydride), poly(ethylene glycol)-sebacic acid, alumina, dispersants, isotherm adsorptio

    Implementasi Deteksi dan Pengenalan Wajah pada Sistem Ujian Online Menggunakan Metode Deep Learning Berbasis Raspberry Pi

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    Penelitian ini bertujuan untuk mengembangkan sistem yang secara otomatis dapat mengenali peserta dalam tes berbasis online untuk efisiensi waktu dan biaya. Sistem ini terdiri dari Raspberry Pi untuk menjalankan algoritma pengenalan wajah, Kamera Pi untuk menangkap gambar peserta dan server lokal untuk menyimpan data peserta. Pada tahap awal penelitian, dibangun sebuah dataset yang berisi foto terbaru peserta dan id peserta. Dataset ini kemudian digunakan dalam proses pembelajaran menggunakan algoritma haarcascade yang merupakan bagian dari metode deep learning untuk menghasilkan sebuah model. Pada tahap pengenalan, gambar peserta dibandingkan dengan model. Peserta yang berhasil dikenali akan secara otomatis dialokasikan ke komputer yang tersedia. Pengujian menunjukkan bahwa sistem berhasil mengenali peserta tes dan yang bukan peserta tes