1,442 research outputs found

    Radiation Hardness and Linearity Studies of CVD Diamonds

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    We report on the behavior of CVD diamonds under intense electromagnetic radiation and on the response of the detector to high density of deposited energy. Diamonds have been found to remain unaffected after doses of 10 MGy of MeV-range photons and the diamond response to energy depositions of up to 250 GeV/cm^3 has been found to be linear to better than 2 %. These observations make diamond an attractive detector material for a calorimeter in the very forward region of the detector proposed for TESLA.Comment: 4 pages, 5 figures; Proceeding for the topical Seminar on Innovative Particle and Radiation Detectors Siena, 21-24 October 2002; to appear in Nucl.Phys. B (Proceedings Supplement

    Charged Higgs Boson Pairs at the LHC

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    We compute the cross section for pair production of charged Higgs bosons at the LHC and compare the three production mechanisms. The bottom-parton scattering process is computed to NLO, and the validity of the bottom-parton approach is established in detail. The light-flavor Drell-Yan cross section is evaluated at NLO as well. The gluon fusion process through a one-loop amplitude is then compared with these two results. We show how a complete sample of events could look, in terms of total cross sections and distributions of the heavy final states.Comment: 15 pages with 8 figure

    Third generation sfermions decays into Z and W gauge bosons: full one-loop analysis

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    The complete one-loop radiative corrections to third generation scalar fermions into gauge bosons Z and W^\pm is considered. We focus on \wt{f}_2 \to Z \wt{f}_1 and \wt{f}_i \to W^\pm \wt{f'}_j (f,f'=t,b). We include both SUSY-QCD, QED and full electroweak corrections. It is found that the electroweak corrections can be of the same order as the SUSY-QCD corrections. The two sets of corrections interfere destructively in some region of parameter space. The full one loop correction can reach 10% in some SUGRA scenario, while in model independent analysis like general MSSM, the one loop correction can reach 20% for large \tan\beta and large trilinear soft breaking terms A_b.Comment: Latex file, 18 pages, 8 figures, version to appear in PR

    Diffractive SUSY particle production at the LHC

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    We give detailed predictions for diffractive SUSY Higgs boson and top squark associated productions at the LHC via the exclusive double pomeron exchange mechanism. We study how the SUSY Higgs cross section and the signal over background ratio are enhanced as a function of tangent beta in different regimes. The prospects are particularly promising in the ``anti-decoupling'' regime, which we study in detail. We also give the prospects for a precise measurement of the top squark mass using the threshold scan of central diffractive associated top squark events at the LHC.Comment: 14 pages, 6 fig

    Electromagnetic Radiation Hardness of Diamond Detectors

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    The behavior of artificially grown CVD diamond films under intense electromagnetic radiation has been studied. The properties of irradiated diamond samples have been investigated using the method of thermally stimulated current and by studying their charge collection properties. Diamonds have been found to remain unaffected after doses of 6.8 MGy of 10 keV photons and 10 MGy of MeV-range photons. This observation makes diamond an attractive detector material for a calorimeter in the very forward region of the proposed TESLA detector.Comment: 19 pages, 9 figure

    CP sensitive observables in chargino production with transverse e±e^{\pm} beam polarization

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    We consider the process e^+e^-\to\ti\chi^+_i\ti\chi^-_j at a linear collider with transverse e±e^{\pm} beam polarization. We investigate the influence of the CP phases on azimuthal asymmetries in e^+e^-\to\ti\chi^+_i\ti\chi^-_j with subsequent two-body decays \ti\chi^-_j\to \ti\nu_{\ell}\ell^- and \ti\chi^-_j\to W^-\ti\chi^0_1. We show that triple product correlations involving the transverse e±e^{\pm} beam polarization vanish if at least one subsequent chargino decay is not observed. We derive this result within the Minimal Supersymmetric Standard Model (MSSM) with complex parameters, however, it holds also in the general MSSM with SUSY flavour violation.Comment: 19 pages, 6 figure

    New semi-blind approach to optimize turbo decoding for a cauchy α-stable impulsive noise channel

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    Knowledge of the noise parameters that contaminate the signal sent is  very important for many communication systems. In this work, we propose a new method to estimate the dispersion parameter of a  symmetric α-stable impulse noise (SαS) of Cauchy, from the received signal only at the iterative decoder (turbo decoder). This method is based on the FLOS (Fractional Lower Order Statistics) and the probability that binds the received signal and the signal sent in BPSK modulation (Binary Phase Shift Keying). The results obtained, in terms of RMSE (Root Mean Square Error) and BER (Bit Error Rate) show the precision and the efficiency of our approach.Keywords: Cauchy impulse noise SαS, dispersion parameter, FLOS, RMSE, BER

    Fuzzy Logic Maximum Structure and State Feedback Control Strategies of the Electrical Car

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    AbstractThis paper treats the design and control of different models and control strategies for an Electric Vehicle (EV). An hybrid controller is designed using a fuzzy logic integrated in Maximum Control Structure (FL-MCS), the FL nonlinear controller involves online estimation of the total reference force which corresponds to a torque reference to be applied to MCS. The second proposed regulator is a states feedback controller using the Linear Quadratic Regulation (LQR) to optimise and to determine the feedback control parameters. The LQR allows reducing the consumption of the energy according to the desired EV's dynamic performances, these lasts can be changed depending on the choice of Q and R matrices. In this work, we apply and validate the proposed control strategies by a comparison between our simulation results and the results of the classical MCS, which has been developed by L2EP (Lille, France) to control the EV speed under Matlab/Simulink

    Associated Production of a Top Quark and a Charged Higgs Boson

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    We compute the inclusive and differential cross sections for the associated production of a top quark along with a charged Higgs boson at hadron colliders to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD) and in supersymmetric QCD. For small Higgs boson masses we include top quark pair production diagrams with subsequent top quark decay into a bottom quark and a charged Higgs boson. We compare the NLO differential cross sections obtained in the bottom parton picture with those for the gluon-initiated production process and find good agreement. The effects of supersymmetric loop contributions are explored. Only the corrections to the Yukawa coupling are sizable in the potential discovery region at the CERN Large Hadron Collider (LHC). All expressions and numerical results are fully differential, permitting selections on the momenta of both the top quark and the charged Higgs boson.Comment: 15 pages, 9 figures; section, figures, equations and references added, version to appear in PRD, 33 pages, 11 figure

    Homogenous UV/Periodate Process for the Treatment of Acid Orange 10 Polluted Water

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    The photoactivated periodate (UV/IO4−) process is used to investigate the degradation of acid orange 10 (AO10) dye. The photodecomposition of periodate ions produces highly reactive radicals (i.e., •OH, IO3•, and IO4•) that accelerate dye degradation. Increasing the initial concentration of periodate to 3 mM enhances the dye removal rate, but over 3 mM periodate, the degradation rate slows down. On the contrary, increasing initial dye concentrations reduces the degradation performance. pH is the most critical factor in AO10 breakdown. Salts slow down the degradation of the dye. However, UV/IO4− is more efficient in distilled water than natural water. Even at low concentrations, surfactants may affect the dye’s decomposition rate. The addition of sucrose reduced the breakdown of AO10. Although tertbutanol is a very effective •OH radical scavenger, it does not affect the dye breakdown even at the highest concentrations. Accordingly, the AO10 degradation is a non-•OH pathway route. According to retrieved data, the photoactivated periodate method eliminated 56.5 and 60.5% of the initial COD after 60 and 120 min of treatment time; therefore, it can be concluded that the UV/IO4− system may treat effluents, especially those containing textile dyes
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