5,619 research outputs found
The Challenge of Determining SUSY Parameters in Focus-Point-Inspired Cases
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
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
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
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
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
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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