990 resultados para 103-641A


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We report the recent charged Higgs search in top quark decays in 2.2/fb CDF data. This is the first attempt to search for charged Higgs using fully reconstructed mass assuming H->c-sbar in small tan beta region. No evidence of a charged Higgs is observed in the CDF data, hence 95% upper limits are placed at B(t->H+b)

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We present an analysis of the mass of the X(3872) reconstructed via its decay to J/psi pi+ pi- using 2.4 fb^-1 of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. The possible existence of two nearby mass states is investigated. Within the limits of our experimental resolution the data are consistent with a single state, and having no evidence for two states we set upper limits on the mass difference between two hypothetical states for different assumed ratios of contributions to the observed peak. For equal contributions, the 95% confidence level upper limit on the mass difference is 3.6 MeV/c^2. Under the single-state model the X(3872) mass is measured to be 3871.61 +- 0.16 (stat) +- 0.19 (syst) MeV/c^2, which is the most precise determination to date.

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The Raman spectrum of crystalline boric acid is recorded using mercuryλ2537 excitation. Fifteen Raman lines, three of them belonging to the lattice spectrum, are reported. Satisfactory assignments of all the observed Raman frequencies are made using the available X-ray crystal structure data. From the presence of a new high frequency Raman band at about 3420 cm.−1 it is suggested that there might be a small number of long, weak O-H....O hydrogen bonds in the crystal, in addition to the hydrogen bonds of moderate strength reported from X-ray diffraction data.

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A combined mass and particle identification fit is used to make the first observation of the decay Bs --> Ds K and measure the branching fraction of Bs --> Ds K relative to Bs --> Ds pi. This analysis uses 1.2 fb^-1 integrated luminosity of pbar-p collisions at sqrt(s) = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron collider. We observe a Bs --> Ds K signal with a statistical significance of 8.1 sigma and measure Br(Bs --> Ds K)/Br(Bs --> Ds pi) = 0.097 +- 0.018(stat) +- 0.009(sys).

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We present new limits on resonant tb production in proton-antiproton collisions at 1.96 TeV, using 1.9 fb^-1 of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a candidate mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W'->tb. We set a new limit on a right-handed W' with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. The cross-section for any narrow, resonant tb production between 750 and 950 GeV is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W' coupling strength versus W' mass over the range 300 to 950 GeV.

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We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W, Z) where one boson decays to a dijet final state. The data correspond to 3.5  fb-1 of integrated luminosity of pp̅ collisions at √s=1.96  TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516±239(stat)±144(syst) diboson candidate events and measure a cross section σ(pp̅ →VV+X) of 18.0±2.8(stat)±2.4(syst)±1.1(lumi)  pb, in agreement with the expectations of the standard model.

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We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V=W,Z) where one boson decays to a dijet final state . The data correspond to 3.5 inverse femtobarns of integrated luminosity of ppbar collisions at sqrt(s)=1.96 TeV collected by the CDFII detector at the Fermilab Tevatron. We observe 1516+/-239(stat)+/-144(syst) diboson candidate events and measure a cross section sigma(ppbar->VV+X) of 18.0+/-2.8(stat)+/-2.4(syst)+/-1.1(lumi) pb, in agreement with the expectations of the standard model.

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We report the first observation of single top quark production using 3.2 fb^-1 of pbar p collision data with sqrt{s}=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m_t=175 GeV/c^2, we measure a cross section of 2.3 +0.6 -0.5 (stat+syst) pb, extract the CKM matrix element value |V_{tb}|=0.91 +-0.11 (stat+syst) 0.07(theory), and set the limit |V_{tb}|>0.71 at the 95% C.L.

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We search for new charmless decays of neutral b-hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb-1 of integrated luminosity, we report the first observation of the B0s->K-pi+ decay, with a significance of 8.2 sigma, and measure BR(B0s->K-pi+)= (5.0+-0.7(stat)+-0.8(syst))*10^{-6}. We also report the first observation of charmless b-baryon decays in the channels Lambda_b -> p pi and Lambda_b -> pK with significances of 6.0 sigma and 11.5 sigma respectively, and we measure BR(Lambda_b->p pi-) = (3.5+-0.6(stat)+-0.9(syst))*10^{-6} and BR(Lambda_b->p K-) = (5.6+-0.8(stat)+-1.5(syst))*10^{-6}. No evidence is found for the decays B0->K+K- and B0s -> pi+pi-, and we set an improved upper limit BR(B0s -> pi+pi-) K+pi-)$ as a reference.

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In the structure of the title compound, C27H39N3O3, each of the (4-oxopiperidin-1-yl)methyl residues adopts a flattened chair conformation (with the N and carbonyl groups being oriented to either,side of the central C-4 plane) and they occupy positions approximatelym orthogonal to the central benzene ring [C-benzene-C-C-methylene-N torsion angles 103.4 (2), -104.4 (3) and 71.9 (3)degrees]; further, two of these residues are oriented to one side of the central benzene ring with the third to the other side. In the crystal packing, supramolecular layers in the ab plane are sustained by C-H center dotcenter dot center dot O interactions.

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Thermotropic liquid crystals are known to display rich phase behavior on temperature variation. Although the nematic phase is orientationally ordered but translationally disordered, a smectic phase is characterized by the appearance of a partial translational order in addition to a further increase in orientational order. In an attempt to understand the interplay between orientational and translational order in the mesophases that thermotropic liquid crystals typically exhibit upon cooling from the high-temperature isotropic phase, we investigate the potential energy landscapes of a family of model liquid crystalline systems. The configurations of the system corresponding to the local potential energy minima, known as the inherent structures, are determined from computer simulations across the mesophases. We find that the depth of the potential energy minima explored by the system along an isochor grows through the nematic phase as temperature drops in contrast to its insensitivity to temperature in the isotropic and smectic phases. The onset of the growth of the orientational order in the parent phase is found to induce a translational order, resulting in a smectic-like layer in the underlying inherent structures; the inherent structures, surprisingly, never seem to sustain orientational order alone if the parent nematic phase is sandwiched between the high-temperature isotropic phase and the low-temperature smectic phase. The Arrhenius temperature dependence of the orientational relaxation time breaks down near the isotropic-nematic transition. We find that this breakdown occurs at a temperature below which the system explores increasingly deeper potential energy minima.

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Revisorn utför ekonomisk kontroll inom sitt uppdrag. Ett vållande av ekonomisk skada när revisorn utför uppdraget innebär att han kan åläggas skadeståndsansvar. På senare tid har revisors vållande vid ekonomisk kontroll prövats av de högsta rättsinstanserna i de nordiska länderna. De högsta rättsinstanserna tenderar att gå långt i sina bedömningar om revisors vållande av ekonomisk skada. De ställer ofta aktsamhetskravet högt då de ålägger revisorerna skadeståndsansvar. I avhandlingen testas revisors skadeståndsansvar enligt en i undersökningen uppbyggd ekonomisk modell. Målsättningen är att vållanderegeln skall leda till ekonomisk effektivitet. Ekonomisk effektivitet prövas genom att en ekonomisk avvägning mellan nyttan och kostnaden med att företa skadeförebyggande åtgärder görs. I den ekonomiska analysen beskrivs revisors vållande i termer av revisors bristande omsorg, medan revisors grova vållande beskrivs som uppenbar försummelse. För undersökningen utgör det nordiska rättsfallsmaterialet ett material där strukturen är likadan, vilket gör det möjligt att pröva ekonomisk effektivitet. Resultatet av den ekonomiska analysen visar att ersättning för förmögenhetsskador inte skall utgöra den egentliga målsättningen. För att kunna begränsa omfattningen av revisors ersättningsansvar så att det ur en samhällsekonomisk synvinkel är ekonomiskt effektivt, bör det formuleras en snäv bedömningsgrund för revisors bristande omsorg. Den ekonomiska analysen påvisar att revisorerna vid bristande omsorg bör åläggas ett administrativt ansvar i form av disciplinära åtgärder. Revisorer skall åläggas skadeståndsansvar endast vid uppenbar försummelse. Genom uppenbar försummelse underlåter revisorerna att förebygga uppenbar förutsebar skada och åsidosätter sitt professionsansvar på ett medvetet sätt.

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During the last few decades there have been far going financial market deregulation, technical development, advances in information technology, and standardization of legislation between countries. As a result, one can expect that financial markets have grown more interlinked. The proper understanding of the cross-market linkages has implications for investment and risk management, diversification, asset pricing, and regulation. The purpose of this research is to assess the degree of price, return, and volatility linkages between both geographic markets and asset categories within one country, Finland. Another purpose is to analyze risk asymmetries, i.e., the tendency of equity risk to be higher after negative events than after positive events of equal magnitude. The analysis is conducted both with respect to total risk (volatility), and systematic risk (beta). The thesis consists of an introductory part and four essays. The first essay studies to which extent international stock prices comove. The degree of comovements is low, indicating benefits from international diversification. The second essay examines the degree to which the Finnish market is linked to the “world market”. The total risk is divided into two parts, one relating to world factors, and one relating to domestic factors. The impact of world factors has increased over time. After 1993, when foreign investors were allowed to freely invest in Finnish assets, the risk level has been higher than previously. This was also the case during the economic recession in the beginning of the 1990’s. The third essay focuses on the stock, bond, and money markets in Finland. According to a trading model, the degree of volatility linkages should be strong. However, the results contradict this. The linkages are surprisingly weak, even negative. The stock market is the most independent, while the money market is affected by events on the two other markets. The fourth essay concentrates on volatility and beta asymmetries. Contrary to many international studies there are only few cases of risk asymmetries. When they occur, they tend to be driven by the market-wide component rather than the portfolio specific element.

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Financing trade between economic agents located in different countries is affected by many types of risks, resulting from incomplete information about the debtor, the problems of enforcing international contracts, or the prevalence of political and financial crises. Trade is important for economic development and the availability of trade finance is essential, especially for developing countries. Relatively few studies treat the topic of political risk, particularly in the context of international lending. This thesis explores new ground to identify links between political risk and international debt defaults. The core hypothesis of the study is that the default probability of debt increases with increasing political risk in the country of the borrower. The thesis consists of three essays that support the hypothesis from different angles of the credit evaluation process. The first essay takes the point of view of an international lender assessing the credit risk of a public borrower. The second investigates creditworthiness assessment of companies. The obtained results are substantiated in the third essay that deals with an extensive political risk survey among finance professionals in developing countries. The financial instruments of core interest are export credit guaranteed debt initiated between the Export Credit Agency of Finland and buyers in 145 countries between 1975 and 2006. Default events of the foreign credit counterparts are conditioned on country-specific macroeconomic variables, corporate-specific accounting information as well as political risk indicators from various international sources. Essay 1 examines debt issued to government controlled institutions and conditions public default events on traditional macroeconomic fundamentals, in addition to selected political and institutional risk factors. Confirming previous research, the study finds country indebtedness and the GDP growth rate to be significant indicators of public default. Further, it is shown that public defaults respond to various political risk factors. However, the impact of the risk varies between countries at different stages of economic development. Essay 2 proceeds by investigating political risk factors as conveivable drivers of corporate default and uses traditional accounting variables together with new political risk indicators in the credit evaluation of private debtors. The study finds links between corporate default and leverage, as well as between corporate default and the general investment climate and measeures of conflict in the debtor country. Essay 3 concludes the thesis by offering survey evidence on the impact of political risk on debt default, as perceived and experienced by 103 finance professionals in 38 developing countries. Taken together, the results of the thesis suggest that various forms of political risk are associated with international debt defaults and continue to pose great concerns for both international creditors and borrowers in developing countries. The study provides new insights on the importance of variable selection in country risk analysis, and shows how political risk is actually perceived and experienced in the riskier, often lower income countries of the global economy.

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Parliaments are political institutions, but they are also places where people work; the MPs and the people who are employed there work, albeit in rather different ways. In this research the focus is on those in a Parliament who work there as employees and managers, and thereby, in some senses, run the organisation. Accordingly, this involves seeing the Parliament as a working environment, for MPs and employees, for men and women. The institution of Parliament is thus here examined by looking at it from a different and new angle. Instead of the usual focus on politicians the focus is on the administration of this institution. The aim is, amongst other things, to increase knowledge and offer different perspectives on democracy and democratic institutions. Unpacking the nearly mythical institution into smaller, more digestible, graspable realities should at the very least help to remind the wider society that although nations, to a certain extent, do need national institutions they should not become mystified or seen as larger than life. Institutions should work on behalf of people and thus be accountable to these same people. The main contribution of this work is to explore and problematise how managing and working is done inside an institution that both largely fulfils the characteristics of a bureaucracy and yet also has added special features that seem to be rather far removed from clear bureaucratic structures. This research offers a new kind of information on working life inside this elite institution. The joys and the struggles of working and managing in this particular public sector organisation are illustrated here and offer a view, a glimpse, into the experiences of managing and working in this House.