3,856 research outputs found

    NLO Electroweak Corrections to Higgs Decay to Two Photons

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    The recent calculation of the next-to-leading order electroweak corrections to the decay of the Standard Model Higgs boson to two photons in the framework of the complex-mass scheme is briefly summarized.Comment: 4 pages, 4 figures, talk given at LCWS08, Chicago, November 200

    Hierarchic models for laminated plates

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    The research conducted in the formulation of hierarchic models for laminated plates is described. The work is an extension of the work done for laminated strips. The use of a single parameter, beta, is investigated that represents the degree to which the equilibrium equations of three dimensional elasticity are satisfied. The powers of beta identify members in the hierarchic sequence. Numerical examples that were analyzed with the proposed sequence of models are included. The results obtained for square plates with uniform loading and homogeneous boundary conditions are very encouraging. Several cross-ply and angle-ply laminates were evaluated and the results compared with those of the fully three dimensional model, computed using MSC/PROBE, and with previously reported work on laminated strips

    NNLO Computational Techniques: the Cases H -> gamma gamma and H -> g g

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    A large set of techniques needed to compute decay rates at the two-loop level are derived and systematized. The main emphasis of the paper is on the two Standard Model decays H -> gamma gamma and H -> g g. The techniques, however, have a much wider range of application: they give practical examples of general rules for two-loop renormalization; they introduce simple recipes for handling internal unstable particles in two-loop processes; they illustrate simple procedures for the extraction of collinear logarithms from the amplitude. The latter is particularly relevant to show cancellations, e.g. cancellation of collinear divergencies. Furthermore, the paper deals with the proper treatment of non-enhanced two-loop QCD and electroweak contributions to different physical (pseudo-)observables, showing how they can be transformed in a way that allows for a stable numerical integration. Numerical results for the two-loop percentage corrections to H -> gamma gamma, g g are presented and discussed. When applied to the process pp -> gg + X -> H + X, the results show that the electroweak scaling factor for the cross section is between -4 % and + 6 % in the range 100 GeV < Mh < 500 GeV, without incongruent large effects around the physical electroweak thresholds, thereby showing that only a complete implementation of the computational scheme keeps two-loop corrections under control.Comment: LaTeX, 70 pages, 8 eps figure

    Planar two-loop master integrals for massive Bhabha scattering: N_f=1 and N_f=2

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    Recent developments in the computation of two-loop master integrals for massive Bhabha scattering are briefly reviewed. We apply a method based on expansions of exact Mellin-Barnes representations and evaluate all planar four-point master integrals in the approximation of small electron mass at fixed scattering angle for the one-flavor case. The same technique is employed to derive and evaluate also all two-loop masters generated by additional fermion flavors. The approximation is sufficient for the determination of QED two-loop corrections for Bhabha scattering in the kinematics planned to be used for the luminosity determination at the ILC.Comment: 10 pages, 3 figures, 1 table, to appear in the proceedings of 8th DESY Workshop on Elementary Particle Theory: Loops and Legs in Quantum Field Theory, Eisenach, Germany, 23-28 Apr 2006; eqns. 22 and 23 correcte

    Argentina y Brasil: Hacia una Alianza Estratégica… con China

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    El presente artículo analiza la relación bilateral entre Brasil y Argentina a la luz de los vínculos que ambos países viene construyendo con la República Popular de China. Se sostiene que la profundización de las interacciones con el país asiático afectan la alianza estratégica que Brasil y Argentina construyeron en la primera década del siglo XXIFil: Actis, Esteban. Universidad Nacional de Rosario. Facultad de Ciencias Politicas y Relaciones Internacionales. Instituto de Investigaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    “Brazil power and multinational corporation”: brazilian multinational corporations, foreign policy and the international insertion of Brazil: an analysis based on the contributions of Robert Gilpin

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    The first decade of the XXI century evidenced transformations in the international order’s financial dimension due to the growth in the so-called emerging powers. An indicator of such phenomenon is the emergence of multinational corporations from the developing world - MNC Latecomers-, turning certain countries, as is the case of Brazil, into net issuers of Foreign Direct Investment flows. In this sense, this paper analyzes the impact that the emergence and consolidation of Brazilian multinational corporations has had since 2003 until now on the foreign policy and the international insertion of Brazil (and vice versa), taking into consideration Robert Gilpin’s classical work, “U.S. power and multinational corporation: the political economy of foreign direct investment.” Gilpin’s framework shall be useful for empirical contrast of this study case.Fil: Actis, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario; Argentin

    The bilateral relationship between Argentina and Brazil (2011-2014): The confluence of domestic and systemic factors for a lower relative intensity in the interactions

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    El presente trabajo tiene como objetivo analizar la dinámica del vínculo bilateral entre Argentina y Brasil entre los años 2011-2014, recorte que coincide con el traspaso del mando presidencial de “Lula” Da Silva a Dilma Rousseff. A partir de la selección de ciertos indicadores, la evidencia señala que la relación estuvo signada por una menor intensidad relativa, tanto en las interacciones económicas como políticas. Para explicar dicho fenómeno se optó por indagar en un conjunto de factores propios del sistema internacional como elementos domésticos de cada una de las unidades estatales analizadas.This study aims to analyze the dynamics of the bilateral relation among Argentina and Brazil between the years 2011-2014, period of time that coincides with the assumption of President Dilma Rousseff. The facts indicate that the relationship was characterized for a moment of lower relative intensity, both in the economic and politics interactions. To explain such phenomenon we opted to dig and interrelated a set of systemic and domestics factors in both countries.Fil: Actis, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Políticas y Relaciones Internacionales. Instituto de Investigaciones; Argentin

    NNLO massive corrections to Bhabha scattering and theoretical precision of BabaYaga@NLO

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    We provide an exact calculation of next-to-next-to-leading order (NNLO) massive corrections to Bhabha scattering in QED, relevant for precision luminosity monitoring at meson factories. Using realistic reference event selections, exact numerical results for leptonic and hadronic corrections are given and compared with the corresponding approximate predictions of the event generator BabaYaga@NLO. It is shown that the NNLO massive corrections are necessary for luminosity measurements with per mille precision. At the same time they are found to be well accounted for in the generator at an accuracy level below the one per mille. An update of the total theoretical precision of BabaYaga@NLO is presented and possible directions for a further error reduction are sketched.Comment: 5 pages, 3 tables, contrib. to proceedings of International Workshop on e+e- collisions: from Phi to Psi, PHIPSI11, BINP, Novosibirsk, Russia, September 19-22, 201
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