LHCb pentaquarks in constituent quark models

The recently discovered $P_c(4380)^+$ and $P_c(4450)^+$ states at LHCb have masses close to the $\bar D\Sigma_c^*$ and $\bar D^*\Sigma_c$ thresholds, respectively, which suggest that they may have significant meson-baryon molecular components. We analyze these states in the framework of a constituent quark model which has been applied to a wide range of hadronic observables, being the model parameters, therefore, completely constrained. The $P_c(4380)^+$ and $P_c(4450)^+$ are studied as molecular states composed by charmed baryons and open charm mesons. Several bound states with the proper binding energy are found in the $\bar D\Sigma_c^*$ and $\bar D^*\Sigma_c$ channels. We discuss the possible assignments of these states from their decay widths. Moreover, two more states are predicted, associated with the $\bar D\Sigma_c$ and $\bar D^* \Sigma_c^*$ thresholds.Comment: 5 pages, 2 table

Estudio de las estructuras familiares a través de la narrativa transmedia: innovación docente

El trabajo de fin de grado presenta una propuesta de intervención basada en la innovación docente en el ámbito de la Educación Superior, concretamente en el campo de actuación de la Educación Social. El análisis central se basa en la utilización de la narrativa transmedia como herramienta socioeducativa en el estudio de las estructuras familiares, fomentando la multifuncionalidad docente y el uso de los medios de comunicación social para analizar temáticas sociales de gran relevancia para los estudios del Grado en cuestión. A modo de conclusión, se relaciona la importancia de la innovación educativa en el Sistema Educativo actual, así como el papel profesionalizador de la Educación Social en el campo de la educación reglada, vinculando competencias y funciones concretas.Grado en Educación Socia

Limitations of the Standard Procedure for the Evaluation of Marble and Limestone for Use in Construction: A Critical Analysis and Proposal for Modification

The selection of natural stone for each specific use must be based on determinations which assess their technical quality and ensure their suitability for the environment in which they will be utilized. Among the criteria to be considered, a petrographic characterization is basic to deduce the behaviour of the stone to external agents. Current European regulations for the valuation and use of a stone present serious constraints in connection with the petrographic characterization and with the definition of some of the technological tests, which can endanger the suitability of a stone for use in construction. Two commercial limestones and one marble, are studied following the existing European Standards, to explain reasonably the behavior of these materials and deduce the most appropriate uses. Finally the results lead to certain recommendations to modify existing regulations

Heavy mesons in the Quark Model

Since the discovery of the $J/\psi$, the quark model was very successful in describing the spectrum and properties of heavy mesons including only $q\bar q$ components. However since 2003, with the discovery of the $X(3872)$, many states that can not be accommodated on the naive quark model have been discovered, and they made unavoidable to include higher Fock components on the heavy meson states. We will give an overview of the success of the quark model for heavy mesons and point some of the states that are likely to be more complicated structures such as meson-meson molecules.Comment: Contribution to the Proceedings of the 15th International Workshop on Meson Physics - MESON201

Welfare Policies and Solidarity Toward the Elderly

In this paper we analyze the effect of welfare policies oriented toward the elderly on solidarity toward the elderly in a sample of European countries. The research question is whether more generous welfare policies crowd out solidarity. For this purpose, we analyze four waves of the SHARE database. We use multilevel analysis to estimate the effect of national variables on transfers toward the elderly, controlling for individual level variables. At the national level we focus on the effect of public spending on policies oriented toward the elderly after controlling for some other relevant variables, such as the proportion of elderly people, female labor force participation and unemployment. Our results indicate that expenditure in social protection toward the elderly has a positive and significant (albeit moderate) effect on the economic support received by the elderly (which is in line with the Crowding-in hypothesis). However, in the case of time transfers, we find that expenditure in social protection toward the elderly has a negative and significant impact on the time transfers received by the elderly (which is consistent with the Crowding-out hypothesis).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Charmonium resonances in the 3.9 GeV/c2c^2 energy region and the X(3915)/X(3930)X(3915)/X(3930) puzzle

An interesting controversy has emerged challenging the widely accepted nature of the $X(3915)$ and the $X(3930)$ resonances, which had initially been assigned to the $\chi_{c0}(2P)$ and $\chi_{c2}(2P)$ $c\bar c$ states, respectively. To unveil their inner structure, the properties of the $J^{PC}\!\!=\!0^{++}$ and $J^{PC}\!\!=\!2^{++}$ charmonium states in the energy region of these resonances are analyzed in the framework of a constituent quark model. Together with the bare $q\bar q$ states, threshold effects due to the opening of nearby meson-meson channels are included in a coupled-channels scheme calculation. We find that the structure of both states is dominantly molecular with a probability of bare $q\bar q$ states lower than $45\%$. Our results favor the hypothesis that $X(3915)$ and $X(3930)$ resonances arise as different decay mechanisms of the same $J^{PC}\!\!=\!2^{++}$ state. Moreover we found an explanation for the recently discovered $M=3860$ MeV$/c^2$ as a $J^{PC}\!\!=\!0^{++}$ $2P$ state and rediscovery the lost $Y(3940)$ as an additional state in the $J^{PC}\!\!=\!0^{++}$ family.Comment: 6 pages, 3 table

Crossing the Border: Self-Selection, Earnings and Individual Migration Decisions

Many empirical studies on the determinants of international migration flows rely exclusively on macro data, and do not account for migrants' self-selection. We analyze a very interesting episode in international migration for which we are able to gather individual-level data covering all relevant countries, namely the exodus of Ecuadorians to Spain and the US in the aftermath of the economic collapse of 1999. Specifically, we produce selection-corrected predictions of counterfactual individual earnings and use them to estimate a discrete-choice migration equation that allows for correlated errors across destinations and a rich structure of migration costs. We find that earnings significantly shape individual migration decisions, even in an episode in which Ecuadorians mostly chose Spain where earnings were lower than in the US, and they contribute to explaining the observed composition of migration flows. Moreover, our estimates show that changes in earnings at a particular destination have a larger effect on destination choice conditional on migration than on the scale of migration.international migration, self-selection, earnings, individual-level data

High temperature packed bed thermal energy storage systems based on low cost materials

294 p.Los sistemas de almacenamiento térmico basados en lecho fijo se presentan hoy en día como una alternativa de bajo coste que permite incrementar sustancialmente la eficiencia de numerosos procesos industriales. En esta tecnología, partículas de un material sólido apiladas formando un lecho son empleadas como medio de almacenamiento térmico. A través de este lecho se hace circular un fluido caloportador el cual cede o recibe el calor en función de si el sistema está en modo de carga o descarga, respectivamente. Teniendo en cuenta lo anterior, en la presente tesis se plantea el uso de materiales cerámicos de bajo coste. En particular, se propone un residuo generado en la producción de hierro y acero, la escoria, y una material natural, mineral de magnetita. Dichos materiales son estudiados en profundidad determinando su estabilidad y principales propiedades térmicas, mecánicas y estructurales que afectan a su comportamiento en sistemas de lecho fijo, a temperaturas de hasta 1000 °C. Además, en esta tesis se desarrolla un modelo teórico para la descripción de los principales mecanismos de transferencia de calor y de dinámica de fluidos inherentes al lecho fijo. Tras su extensiva validación con resultados experimentales, dicho modelo es utilizado para la elaboración de una guía para el diseño optimizado de esta tipología de sistemas de almacenamiento térmico. Finalmente, el trabajo realizado se completa con el diseño e integración de los sistemas estudiados en tres entornos industriales con elevada producción o demanda de energía térmica. En particular, se demuestra el gran potencial de estos sistemas en la recuperación de calor de los gases a alta temperatura generados en una acería de tecnología de horno de arco eléctrico; en la captación del calor generado en la etapa de compresión en una central de almacenamiento en aire comprimido, y su posterior reutilización en el proceso de expansión; y en una central termo-solar para extender el número de horas de producción eléctrica.CIC Energigun