A clean signal for a top-like isosinglet fermion at the Large Hadron Collider

We predict a clean signal at the Large Hadron Collider ($\sqrt s)$=14 TeV for a scenario where there is a top-like, charge +2/3 vectorlike isosinglet fermion. Such a quark, via mixing with the standard model top, can undergo decays via both flavour-changing Z-boson coupling and flavour-changing Yukawa interactions. We concentrate on the latter channel, and study the situation where, following its pair-production, the heavy quark pair gives rise to two tops and two Higgs boson. We show that the case where each Higgs decays in the $b\bar{b}$ channel, there can be a rather distinct and background-free signal that can unveil the existence of the vectorlike isosinglet quark of this kind.Comment: 14 pages, 5 figures, 4 table

The Effective Lagrangian for Bulk Fermions in Models with Extra Dimensions

We compute the dimension 6 effective Lagrangian arising from the tree level integration of an arbitrary number of bulk fermions in models with warped extra dimensions. The coefficients of the effective operators are written in terms of simple integrals of the metric and are valid for arbitrary warp factors, with or without an infrared brane, and for a general Higgs profile. All relevant tree level fermion effects in electroweak and flavor observables can be computed using this effective Lagrangian.Comment: 22 pages. V2: typos corrected, matches published versio

Memoria Académica 2014-2015

El CABD es un centro mixto de investigación. Actualmente, el centro lo ocupan 19 grupos trabajando en desarrollo de ratón, pez cebra, Xenopus, Drosophila y Caenorhabditis, así como estudiando control del ciclo celular en levaduras, regulación génica en bacterias y estrés oxidativo. El CABD es el único centro español especializado en el estudio de la Biología del Desarrollo. Esta especialidad investiga los mecanismos genéticos y moleculares que controlan cómo las células crecen, se comunican y se diferencian formando órganos complejos. Se ha comprobado que los genes que controlan el desarrollo animal están regulados de modo anómalo en muchas enfermedades humanas. Por tanto, el conocimiento de la función normal de estos genes ayudará a diseñar nuevas estrategias para prevenir o solucionar estos problemas. El CABD se encuentra en fase de expansión, teniendo como objetivo atraer tanto a científicos españoles como extranjeros. El Centro está cofinanciado por el Consejo Superior de Investigaciones Científicas (CSIC), la Junta de Andalucía y la Universidad Pablo de Olavide (UPO), de Sevilla. La edificación y el equipamiento fueron costeados con fondos de la Unión Europea.N

Memoria Curso Académico 2013-2014

El CABD es un centro mixto financiado por el Consejo Superior de Investigaciones Científicas, la Junta de Andalucía y la Universidad Pablo de Olavide. Actualmente el centro lo ocupan 17 grupos trabajando en desarrollo de ratón, pez cebra, Xenopus, Drosophila y Caenorhabditis, así como estudiando control del ciclo celular en levaduras, regulación génica en bacterias y estrés oxidativo. El CABD es el único centro español especializado en el estudio de la Biología del Desarrollo. Esta especialidad investiga los mecanismos genéticos y moleculares que controlan cómo las células crecen, se comunican y se diferencian formando órganos complejos. Se ha comprobado que los genes que controlan el desarrollo animal están regulados de modo anómalo en muchas enfermedades humanas. Por tanto, el conocimiento de la función normal de estos genes ayudará a diseñar nuevas estrategias para prevenir o solucionar estos problemas. El Centro está cofinanciado por el Consejo Superior de Investigaciones Científicas (CSIC), la Junta de Andalucía y la Universidad Pablo de Olavide (UPO), de Sevilla. La edificación y el equipamiento fueron costeados con fondos de la Unión Europea.N

Memoria Curso Académico 2012-2013

El CABD es un centro mixto financiado por el Consejo Superior de Investigaciones Científicas, la Junta de Andalucía y la Universidad Pablo de Olavide. Actualmente, el Centro lo ocupan 17 grupos trabajando en desarrollo de ratón, pez cebra, Xenopus, Drosophila y Caenorhabditis, así como estudiando control del ciclo celular en levaduras, regulación génica en bacterias y estrés oxidativo. El CABD es el único centro español especializado en el estudio de la Biología del Desarrollo. Esta especialidad investiga los mecanismos genéticos y moleculares que controlan cómo las células crecen, se comunican y se diferencian formando órganos complejos. Se ha comprobado que los genes que controlan el desarrollo animal están regulados de modo anómalo en muchas enfermedades humanas. Por tanto, el conocimiento de la función normal de estos genes ayudará a diseñar nuevas estrategias para prevenir o solucionar estos problemas. El Centro está cofinanciado por el Consejo Superior de Investigaciones Científicas (CSIC), la Junta de Andalucía y la Universidad Pablo de Olavide (UPO), de Sevilla. La edificación y el equipamiento fueron costeados con fondos de la Unión Europea.N

An Entangled Model for Sustainability Indicators.

Nowadays the challenge for humanity is to find pathways towards sustainable development. Decision makers require a set of sustainability indicators to know if the sustainability strategies are following those pathways. There are more than one hundred sustainability indicators but they differ on their relative importance according to the size of the locality and change on time. The resources needed to follow these sustainability indicators are scarce and in some instances finite, especially in smaller regions. Therefore strategies to select set of these indicators are useful for decision makers responsible for monitoring sustainability. In this paper we propose a model for the identification and selection of a set of sustainability indicators that adequately represents human systems. In developing this model, we applied evolutionary dynamics in a space where sustainability indicators are fundamental entities interconnected by an interaction matrix. we used a fixed interaction that simulates the current context for the city of Cuernavaca, México as an example. We were able to identify and define relevant sets indicators for the system by using the Pareto principle. In this case we identified a set of sixteen sustainability indicators with more than 80% of the total strength. This set presents resilience to perturbations. For the Tangled Nature framework we provided a manner of treating different contexts (i.e., cities, counties, states, regions, countries, continents or the whole planet), dealing with small dimensions. This model provides decision makers with a valuable tool to select sustainability indicators set for towns, cities, regions, countries, continents or the entire planet according to a coevolutionary framework. The social legitimacy can arise from the fact that each individual indicator must be selected from those that are most important for the subject community

Top quark tensor couplings

We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the $tbW$ vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of the electroweak SM correction is close to 10$$ of the leading contribution given by the QCD gluon exchange. We also find that the electroweak real and imaginary parts for the anomalous right coupling are almost of the same order of magnitude. The one loop SM prediction for the real part of the left coupling is close to the 3$\sigma$ discovery limit derived from $b\rightarrow s \gamma$. Besides, taking into account that the predictions of new physics interactions are also at the level of a few percents when compared with the one loop QCD gluon exchange, these electroweak corrections should be taken into account in order to disentangle new physics effects from the standard ones. These anomalous tensorial couplings of the top quark will be investigated at the LHC in the near future where sensitivity to these contributions may be achieved.Comment: 16 pages, 2 figure

Neutrino physics at large colliders

Large colliders are not sensitive to light neutrino masses and character, but they can produce new heavy neutrinos, allowing also for the determination of their Dirac or Majorana nature. We review the discovery limits at the next generation of large colliders.Comment: LaTeX 32 pages. This review summarises and extends work presented at several conferences. To appear in the proceedings of CORFU2005. References adde

Model-Independent Searches for New Quarks at the LHC

New vector-like quarks can have sizable couplings to first generation quarks without conflicting with current experimental constraints. The coupling with valence quarks and unique kinematics make single production the optimal discovery process. We perform a model-independent analysis of the discovery reach at the Large Hadron Collider for new vector-like quarks considering single production and subsequent decays via electroweak interactions. An early LHC run with 7 TeV center of mass energy and 1 fb-1 of integrated luminosity can probe heavy quark masses up to 1 TeV and can be competitive with the Tevatron reach of 10 fb-1. The LHC with 14 TeV center of mass energy and 100 fb-1 of integrated luminosity can probe heavy quark masses up to 3.7 TeV for order one couplings.Comment: 37 pages, 11 figures, 7 table

Loop lessons from Wilson loops in N=4 supersymmetric Yang-Mills theory

N=4 supersymmetric Yang-Mills theory exhibits a rather surprising duality of Wilson-loop vacuum expectation values and scattering amplitudes. In this paper, we investigate this correspondence at the diagram level. We find that one-loop triangles, one-loop boxes, and two-loop diagonal boxes can be cast as simple one- and two- parametric integrals over a single propagator in configuration space. We observe that the two-loop Wilson-loop "hard-diagram" corresponds to a four-loop hexagon Feynman diagram. Guided by the diagrammatic correspondence of the configuration-space propagator and loop Feynman diagrams, we derive Feynman parameterizations of complicated planar and non-planar Feynman diagrams which simplify their evaluation. For illustration, we compute numerically a four-loop hexagon scalar Feynman diagram.Comment: 20 pages, many figures. Two references added. Published versio