5,619 research outputs found

    The Challenge of Determining SUSY Parameters in Focus-Point-Inspired Cases

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    We discuss the potential of combined LHC and ILC experiments for SUSY searches in a difficult region of the parameter space, in which all sfermion masses are above the TeV scale. Precision analyses of cross sections of light chargino production and forward--backward asymmetries of decay leptons and hadrons at the ILC, together with mass information on \tilde{\chi}^0_2 and squarks from the LHC, allow us to fit rather precisely the underlying fundamental gaugino/higgsino MSSM parameters and to constrain the masses of the heavy virtual sparticles. For such analyses the complete spin correlations between the production and decay processes have to be taken into account. We also took into account expected experimental uncertainties.Comment: 4 pages, talk given at XLI Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, 11-18 Mar 200

    Preventing Incomplete/Hidden Requirements: Reflections on Survey Data from Austria and Brazil

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    Many software projects fail due to problems in requirements engineering (RE). The goal of this paper is analyzing a specific and relevant RE problem in detail: incomplete/hidden requirements. We replicated a global family of RE surveys with representatives of software organizations in Austria and Brazil. We used the data to (a) characterize the criticality of the selected RE problem, and to (b) analyze the reported main causes and mitigation actions. Based on the analysis, we discuss how to prevent the problem. The survey includes 14 different organizations in Austria and 74 in Brazil, including small, medium and large sized companies, conducting both, plan-driven and agile development processes. Respondents from both countries cited the incomplete/hidden requirements problem as one of the most critical RE problems. We identified and graphically represented the main causes and documented solution options to address these causes. Further, we compiled a list of reported mitigation actions. From a practical point of view, this paper provides further insights into common causes of incomplete/hidden requirements and on how to prevent this problem.Comment: in Proceedings of the Software Quality Days, 201

    CP violation at one loop in the polarization-independent chargino production in e+e- collisions

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    Recently Osland and Vereshagin noticed, based on sample calculations of some box diagrams, that in unpolarised e+e- collisions CP-odd effects in the non-diagonal chargino-pair production process are generated at one-loop. Here we perform a full one-loop analysis of these effects and point out that in some cases the neglected vertex and self-energy contributions may play a dominant role. We also show that CP asymmetries in chargino production are sensitive not only to the phase of mu parameter in the chargino sector but also to the phase of stop trilinear coupling A_t.Comment: 14 pages, 5 figure

    Substituent Effect on the Association Equilibria of Free Radical Anions. Electrochemical Reduction of p-Substituted Nitrobenzenes in N,N-Dimethylformamide

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    Association constants between p-substituted nitrobenzene anion radicals, formed by reduction of the parent molecules at a dropping mercuryelectrode, and tetraethylammonium cation in N,N-dimethylformamide have been determined by studying the variation in the half-wave potential with solution composition. The association constant was observed to depend on the substituent effect; it was shown that the Hammett equation in the form log K" = - 1.550 + 2.77 is fulfilled.The dependence of logK" vs. the hyperfine splitting constant (from ESR spectra) proper for N-nuclei in nitro-group of radical anions is also discussed

    Low frequency elastic wave propagation in 2D locally resonant phononic crystal with asymmetric resonator

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    The resonance modes and the related effects to the transmission of elastic waves in a two dimensional phononic crystal formed by periodic arrangements of a two blocks unit cell in one direction are studied. The unit cell consists of two asymmetric elliptic cylinders coated with silicon rubber and embedded in a rigid matrix. The modes are obtained by the semi-analytic method in the least square collocation scheme and confirmed by the finite element method simulations. Two resonance modes, corresponding to the vibration of the cylinder along the long and short axes, give rise to resonance reflections of elastic waves. One mode in between the two modes, related to the opposite vibration of the two cylinders in the unit cell in the direction along the layer, results in the total transmission of elastic waves due to zero effective mass density at the frequency. The resonance frequency of this new mode changes continuously with the orientation angle of the elliptic resonator.Comment: 17 pages, 7 figure

    Electroreduction of Benzalacetone in N,N -dimethylformamide

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    The electrochemical reduction of benzalacetone (BA) has been studied at mercury cathodes in N,N-dimethylformamide solutions by the techniques of cyclic voltammetry and controlled potential coulometry. The radical anion (BA\u27-) forms ion pairs with tetraethylammonium cations and then disappears in oligomerization processes. Atentative structureof the dimer BA- BA"-... (C2H5)4N+is suggested on the basis of quantum mechanical callations
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