1,442 research outputs found
Radiation Hardness and Linearity Studies of CVD Diamonds
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
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
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
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
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 beam polarization
We consider the process e^+e^-\to\ti\chi^+_i\ti\chi^-_j at a linear
collider with transverse 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 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
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
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
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
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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