An example of resonance saturation at one loop

We argue that the large-Nc expansion of QCD can be used to treat a Lagrangian of resonances in a perturbative way. As an illustration of this we compute the L_10 coupling of the Chiral Lagrangian by integrating out resonance fields at one loop. Given a Lagrangian and a renormalization scheme, this is how in principle one can answer in a concrete and unambiguous manner questions such as at what scale resonance saturation takes place.Comment: 9 pages, 5 figures. Enlarged discussion, results unchanged. To be published in Phys. Rev.

Duality Violation and the K --> pi pi Electroweak Penguin Operator Matrix Elements from Hadronic Tau Decays

We discuss a preliminary study of the impact of duality violations on extractions from tau decay data of the D=6 VEVs which determine chiral limit Standard Model K-->pi pi matrix elements of the electroweak penguin operators.Comment: 4 pages, 5 figures, prepared for the Proceedings of the 11th Particle and Nuclear Intersections Conference (PANIC 2011), Boston, USA, July 24-29, 201

A relativistic chiral quark model for pseudoscalar emission from heavy mesons

The amplitudes for one-pion mediated transitions between heavy meson excited states are obtained in the framework of the relativistic chiral quark model. The effective coupling constants to pions and the decay widths of excited heavy mesons with l<=2 for non-radially excited, and the l=0 radially excited mesons are presented for both charmed and beauty mesons. We also discuss the allowed decays of strange excited heavy mesons by emission of a K-meson.Comment: 20 pages, revte

Long-distance dimension-eight operators in B_K

Besides their appearance at short distances \gtrsim 1/M_W, local dimension-eight operators also contribute to kaon matrix elements at long distances of order \gtrsim 1/mu_ope, where mu_ope is the scale controlling the Operator Product Expansion in pure QCD, without weak interactions. This comes about in the matching condition between the effective quark Lagrangian and the Chiral Lagrangian of mesons. Working in dimensional regularization and in a framework where these effects can be systematically studied, we calculate the correction from these long-distance dimension-eight operators to the renormalization group invariant B_K factor of K^0-K^0bar mixing, to next-to-leading order in the 1/Nc expansion and in the chiral limit. The correction is controlled by the matrix element <0|\bar s_L \tilde{G}_{mu nu}gamma^mu d_L|K^0>, is small, and lowers B_K.Comment: 14 pages, LaTeX. Explanatory comments added to match version in journa

Decay of pseudoscalars into lepton pairs and large-Nc QCD

The counterterm combination that describes the decay of pseudoscalar mesons into charged lepton pairs at lowest order in chiral perturbation theory is considered within the framework of QCD in the limit of a large number of colours Nc. When further restricted to the lowest meson dominance approximation to large-Nc QCD, our results agree well with the available experimental data.Comment: 5 pages, 2 figure

Electroweak Hadronic Contributions to the muon g-2

We reanalyze the two-loop electroweak hadronic contributions to the muon g-2 that may be enhanced by large logarithms. The present evaluation is improved over those already existing in the literature by the implementation of the current algebra Ward identities and the inclusion of the correct short-distance QCD behaviour of the relevant hadronic Green's function.Comment: 29 pages, 6 figures, LaTeX. Typos fixe

Influence of new irrigated croplands on wild boar (Sus scrofa) road kills in NW Spain

Influencia de los nuevos cultivos en regadío sobre las colisiones de vehículos con jabalí (Sus scrofa) en el Noroeste de España Las poblaciones de jabalí han aumentado en número y distribución en las últimas décadas en España. En dicho aumento, interviene la mayor extensión de los cultivos de maíz (Zea mays); donde la especie encuentra refugio y alimento. La expansión de la especie, provoca un aumento de colisiones de jabalí con vehículos (WBVC). El presente trabajo trata de la distribución espacio–temporal del WBVC en la meseta norte española. Normalmente, el WBVC se relaciona con la velocidad, el volumen de tráfico y/o cubierta forestal. Sin embargo, el maizal resulta la variable más relacionada en atropellos con jabalí en la meseta norte. Se dan algunas recomendaciones para evitar futuras colisiones en esta área.Influencia de los nuevos cultivos en regadío sobre las colisiones de vehículos con jabalí (Sus scrofa) en el Noroeste de España Las poblaciones de jabalí han aumentado en número y distribución en las últimas décadas en España. En dicho aumento, interviene la mayor extensión de los cultivos de maíz (Zea mays); donde la especie encuentra refugio y alimento. La expansión de la especie, provoca un aumento de colisiones de jabalí con vehículos (WBVC). El presente trabajo trata de la distribución espacio–temporal del WBVC en la meseta norte española. Normalmente, el WBVC se relaciona con la velocidad, el volumen de tráfico y/o cubierta forestal. Sin embargo, el maizal resulta la variable más relacionada en atropellos con jabalí en la meseta norte. Se dan algunas recomendaciones para evitar futuras colisiones en esta área.In recent decades, wild boar populations have increased both in number and distribution. This rise is partly related to the increase in cropland devoted to maize (Zea mays) cultivation, as wild boar find food and refuge in these areas. This population expansion has led to an increase in the number of wild boar vehicle collisions (WBVCs). The goal of the present study was to evaluate a set of spatio–temporal factors that influence WBVCs related to maize crops on the Northern Spanish Plateau (the region of Castile and Leon). We compared the maize pattern with the factors related to total WBVC numbers. We observed that whereas the total occurrence of WBVCs usually increased with forest cover and speed and traffic volumes, maize areas were one of the main explanatory variables in plateau models. To avoid collisions in these areas in future, a number of mitigation measures are outlined

Interactive-predictive neural multimodal systems

[EN] Despite the advances achieved by neural models in sequence to sequence learning, exploited in a variety of tasks, they still make errors. In many use cases, these are corrected by a human expert in a posterior revision process. The interactive-predictive framework aims to minimize the human effort spent on this process by considering partial corrections for iteratively refining the hypothesis. In this work, we generalize the interactive-predictive approach, typically applied in to machine translation field, to tackle other multimodal problems namely, image and video captioning. We study the application of this framework to multimodal neural sequence to sequence models. We show that, following this framework, we approximately halve the effort spent for correcting the outputs generated by the automatic systems. Moreover, we deploy our systems in a publicly accessible demonstration, that allows to better understand the behavior of the interactive-predictive framework.The research leading to these results has received funding from MINECO under grant IDIFEDER/2018/025 Sistemas de fabricacion inteligentes para la industria 4.0, action co-funded by the European Regional Development Fund 2014-2020 (FEDER), and from the European Commission under grant H2020, reference 825111 (DeepHealth). We also acknowledge NVIDIA Corporation for the donation of GPUs used in this work.Peris, Á.; Casacuberta Nolla, F. (2019). Interactive-predictive neural multimodal systems. Springer. 16-28. https://doi.org/978-3-030-31332-6_2S162

Vector Meson Dominance as a first step in a systematic approximation: the pion vector form factor

Pade Approximants can be used to go beyond Vector Meson Dominance in a systematic approximation. We illustrate this fact with the case of the pion vector form factor and extract values for the first two coefficients of its Taylor expansion. Pade Approximants are shown to be a useful and simple tool for incorporating high-energy information, allowing an improved determination of these Taylor coefficients.Comment: 13 pages, 7 figure