3,674 research outputs found

    Updated NNLO QCD predictions for the weak radiative B-meson decays

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    Weak radiative decays of the B mesons belong to the most important flavor changing processes that provide constraints on physics at the TeV scale. In the derivation of such constraints, accurate standard model predictions for the inclusive branching ratios play a crucial role. In the current Letter we present an update of these predictions, incorporating all our results for the O(alpha_s^2) and lower-order perturbative corrections that have been calculated after 2006. New estimates of nonperturbative effects are taken into account, too. For the CP- and isospin-averaged branching ratios, we find B_{s gamma} = (3.36 +_ 0.23) * 10^-4 and B_{d gamma} = 1.73^{+0.12}_{-0.22} * 10^-5, for E_gamma > 1.6GeV. Both results remain in agreement with the current experimental averages. Normalizing their sum to the inclusive semileptonic branching ratio, we obtain R_gamma = ( B_{s gamma} + B_{d gamma})/B_{c l nu} = (3.31 +_ 0.22) * 10^-3. A new bound from B_{s gamma} on the charged Higgs boson mass in the two-Higgs-doublet-model II reads M_{H^+} > 480 GeV at 95%C.L.Comment: journal version, 5 pages, no figure

    Maritime Spatial Planning Transboundary Pilot Projects and their implication in the national process in Spain

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    Los procesos de Ordenación del Espacio Marítimo (OEM) ya se están aplicando en muchas partes del mundo siendo Europa un punto caliente debido a la aprobación de la Directiva 2014/89/UE del Parlamento Europeo y del Consejo, de 23 de julio de 2014, por la que se establece un marco para la OEM, que obligaba a todos los Estados miembros costeros a tener planes aprobados para marzo de 2021. Para facilitar esto, se asignan fondos europeos específicos para apoyar el desarrollo de proyectos transfronterizos de ordenación del espacio marítimo entre países vecinos. Estos proyectos tienen principalmente dos objetivos, uno es proporcionar a los Estados conocimientos, capacidad y metodologías para aplicarlos en los procesos nacionales de ordenación del territorio, y otro es facilitar la coherencia entre los planes de los países que comparten la misma cuenca marítima. Este trabajo presenta una visión general del proceso español de MSP, y cómo algunos de los resultados que surgieron de estos proyectos piloto pueden ser incorporados al proceso nacional

    Complete Anatomy of B -> K*ll and its angular distribution

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    We present a complete and optimal set of observables for the exclusive 4-body B meson decay B -> K*(->K pi) l+l- in the low dilepton mass region, that contains a maximal number of clean observables. This basis of observables is built in a systematic way. We show that all the previously defined observables and any observable that one can construct, can be expressed as a function of this basis. This set of observables contains all the information that can be extracted from the angular distribution in the cleanest possible way. We provide explicit expressions for the full and the uniangular distributions in terms of this basis. The conclusions presented here can be easily extended to the large-q^2 region. We study the sensitivity of the observables to right-handed currents and scalars. Finally, we present for the first time all the symmetries of the full distribution including massive terms and scalar contributions.Comment: 37 pages, 12 Figures. Corrected typo in Eqs. (29) and (44). Results and conclusions unchange

    Implications from clean observables for the binned analysis of B -> K*ll at large recoil

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    We perform a frequentist analysis of q^2-dependent B-> K*(->Kpi)ll angular observables at large recoil, aiming at bridging the gap between current theoretical analyses and the actual experimental measurements. We focus on the most appropriate set of observables to measure and on the role of the q^2-binning. We highlight the importance of the observables P_i exhibiting a limited sensitivity to soft form factors for the search for New Physics contributions. We compute predictions for these binned observables in the Standard Model, and we compare them with their experimental determination extracted from recent LHCb data. Analyzing b->s and b->sll transitions within four different New Physics scenarios, we identify several New Physics benchmark points which can be discriminated through the measurement of P_i observables with a fine q^2-binning. We emphasise the importance (and risks) of using observables with (un)suppressed dependence on soft form factors for the search of New Physics, which we illustrate by the different size of hadronic uncertainties attached to two related observables (P_1 and S_3). We illustrate how the q^2-dependent angular observables measured in several bins can help to unravel New Physics contributions to B-> K*(->Kpi)ll, and show the extraordinary constraining power that the clean observables will have in the near future. We provide semi-numerical expressions for these observables as functions of the relevant Wilson coefficients at the low scale.Comment: 50 pages, 21 figures. Improved form factor analysis, conclusions unchanged. Plots with full resolution. Version published in JHE

    Flavour constraints on scenarios with two or three heavy squark generations

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    We re-assess constraints from flavour-changing neutral currents in the kaon system on supersymmetric scenarios with a light gluino, two heavy generations of squarks and a lighter third generation. We compute for the first time limits in scenarios with three heavy squark families, taking into account QCD corrections at the next-to-leading order. We compare our limits with those in the case of two heavy families. We use the mass insertion approximation and consider contributions from gluino exchange to constrain the mixing between the first and second squark generation. While it is not possible to perform a general analysis, we assess the relevance of each kind of flavour- and CP-violating parameters. We also provide ready to use magic numbers for the computation of the Wilson coefficients at 2 GeV for these scenarios.Comment: 23 pages, 14 figures; v3: matches published version (contains improvements in the presentation and clarifications

    Transboundary cooperation and Mechanisms for Maritime Spatial Planning implementation. SIMNORAT Project

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    El proyecto SIMNORAT, Supporting Implementation of Maritime Spatial Planning in the Northern European Atlantic region (SIMNORAT), fue un proyecto cofundado por la UE de ordenación del espacio marítimo desarrollado en la región atlántica. Los objetivos del proyecto eran apoyar a los Estados miembros (EM) para aplicar la Directiva 2014/89/UE del Parlamento Europeo y del Consejo, de 23 de julio de 2014, por la que se establece un marco para la ordenación del espacio marítimo (OEM); y poner en marcha y llevar a cabo iniciativas concretas y transfronterizas de OEM entre los EM participantes en el proyecto (España, Francia y Portugal). Para desarrollar y probar aspectos de la ordenación del espacio marítimo con el fin de elaborar directrices y recomendaciones útiles en un contexto transfronterizo, las autoridades competentes de los países también participaron en el proyecto. Los resultados de SIMNORAT, como el desarrollo de una metodología conceptual para la ordenación del espacio marítimo transfronterizo, el análisis de las herramientas y los datos aplicados en el proceso de ordenación del espacio marítimo, la evaluación de las demandas y tendencias espaciales de los sectores marítimos, y la participación de las partes interesadas, ayudaron a identificar las mejores prácticas en los aspectos científicos, técnicos y sociales de la ordenación del espacio marítimo para una cooperación eficaz, especialmente en las áreas de estudio de casos transfronterizos, para mejorar la aplicación de la Directiva sobre ordenación del espacio marítimo en cada país con esfuerzos de colaboración y una visión común. Esto, a su vez, puede apoyar la creación del marco adecuado para desarrollar una economía azul sostenible en la región, gestionando el sistema socioecológico asociado en un entorno cambiante

    EOS: a software for flavor physics phenomenology

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    EOS is an open-source software for a variety of computational tasks in flavor physics. Its use cases include theory predictions within and beyond the Standard Model of particle physics, Bayesian inference of theory parameters from experimental and theoretical likelihoods, and simulation of pseudo events for a number of signal processes. EOS ensures high-performance computations through a C++ back-end and ease of usability through a Python front-end. To achieve this flexibility, EOS enables the user to select from a variety of implementations of the relevant decay processes and hadronic matrix elements at run time. In this article, we describe the general structure of the software framework and provide basic examples. Further details and in-depth interactive examples are provided as part of the EOS online documentation

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

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    A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu
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