Dark photon searches with atomic transitions

Dark matter could be made up of dark photons, massive but very light particles whose interactions with matter resemble those of usual photons but suppressed by a small mixing parameter. We analyze the main approaches to dark photon interactions and how they can be applied to direct detection experiments which test different ranges of masses and mixings. A new experiment based on counting dark photons from induced atomic transitions in a target material is proposed. This approach appears to be particularly appropriate for dark photon detection in the meV mass range, extending the constraints in the mixing parameter by up to eight orders of magnitude with respect to previous experiments.Comment: 16 pages, 3 figure

Few-body decay and recombination in nuclear astrophysics

Three-body continuum problems are investigated for light nuclei of astrophysical relevance. We focus on three-body decays of resonances or recombination via resonances or the continuum background. The concepts of widths, decay mechanisms and dynamic evolution are discussed. We also discuss results for the triple $\alpha$ decay in connection with $2^+$ resonances and density and temperature dependence rates of recombination into light nuclei from $\alpha$-particles and neutrons.Comment: 9 pages, 8 figures. Proceedings of the 21st European Few Body Conference held in Salamanca (Spain) in August-September 201

Polar optical phonons in core-shell semiconductor nanowires

We obtain the the long-wavelength polar optical vibrational modes of semiconductor core-shell nanowires by means of a phenomenological continuum model. A basis for the space of solutions is derived, and by applying the appropriate boundary conditions, the transcendental equations for the coupled and uncoupled modes are attained. Our results are applied to the study of the GaAs-GaP core-shell nanowire, for which we calculate numerically the polar optical modes, analyzing the role of strain in the vibrational properties of this nanosystem

Salutogenic interventions and health effects : a scoping review of the literature

Objective To explore the typology of implemented salutogenic interventions and the health effects described by the authors. Method A scoping review of the literature published (PubMed, Embase, Web of Science and Scopus) over the last ten years (2007-2016) was conducted. Articles that included interventions with assessments of health outcomes were selected for this review. The kappa index (86.4%) was calculated for the classification and extraction of information. Results 61 papers were selected out of the 676 works identified. These were categorized into individual, grouped, mixed and intersectoral interventions. A total of 85% of the interventions described positive effects. Adverse effects were not reported. Methodological limitations were identified in 75% of the papers. The interventions addressed a large variety of topics, especially in the field of mental health and chronic diseases. Collective actions described more positive effects. Intersectoral actions were the only type of interventions to have approached the impact of mortality reduction. Conclusions Findings support the existence of positive health effects of salutogenic approaches. Important methodological limitations were identified, such as biases in the selection of participants and sample sizes. Studies need to be conducted with improved monitoring and evaluation designs. A more robust theoretical framework and tools to evaluate the salutogenic contents are needed

Polynomial algebras and exact solutions of general quantum non-linear optical models I: Two-mode boson systems

We introduce higher order polynomial deformations of $A_1$ Lie algebra. We construct their unitary representations and the corresponding single-variable differential operator realizations. We then use the results to obtain exact (Bethe ansatz) solutions to a class of 2-mode boson systems, including the Boson-Einstein Condensate models as special cases. Up to an overall factor, the eigenfunctions of the 2-mode boson systems are given by polynomials whose roots are solutions of the associated Bethe ansatz equations. The corresponding eigenvalues are expressed in terms of these roots. We also establish the spectral equivalence between the BEC models and certain quasi-exactly solvable Sch\"ordinger potentials.Comment: 20 pages, final version to appear in J. Phys. A: Math. Theor

A SENSITIVITY ANALYSIS OF ORGANIC VERSUS CONVENTIONAL SYSTEMS OF SHEEP-FARMING

In the Mediterranean Agriculture, the organic production constitutes a real possibility for sustainable development, it can keep a population in these areas and provide it with a decent work. This paper try to establish differences between conventional and organic systems of production, so that observation of these differences would lead to conclusions relating to the level of efficiency of one system as against the other. To achieve this objective, the research team analyzed the evolution of seventeen milk sheep farms in various places in the Castilla y León Region for a whole year. The study consisted in the modeling of the results of a Cobb-Douglas production function. The findings reveal that organic farms have higher production levels with the same combination of inputs. This result is a guarantee of future for this type of production and guarantee of feasibility for these areas

Estrategias de intervención tutorial en la universidad: una experiencia para la formación integral del alumnado de nuevo ingreso

The requirements that the university education raises in the frame of the EEES make the putting necessary in practice of strategies that allow to achieve a more integral vision of the formation of the student. The university tutoring allows an approximation the budgets that define the process of European Convergence, since across the same one there is reached a more integral vision of the formative process, a major autonomy of the student body and a better preparation along the life. In this article there is defined the model of action who follows in the Faculty of Education of the University of La Laguna (Spain) and there are described the results obtained in a program with students of the first course.Las exigencias que plantea la enseñanza universitaria en el marco del EEES hacen necesario la puesta en práctica de estrategias que permitan lograr una visión más integral de la formación del alumnado. La tutoría universitaria permite un acercamiento a los presupuestos que definen el proceso de Convergencia Europea, puesto que a través de la misma se alcanza una visión más integral del proceso formativo, una mayor autonomía del alumnado y una mejor preparación a lo largo de la vida. En este artículo se define el modelo de actuación que se sigue en la Facultad de Educación de la Universidad de La Laguna (España) y se describen los resultados obtenidos en un programa con estudiantes de primer curso

El asesoramiento y la tutoría de carrera en la Enseñanza Superior : resultados de un programa de atención al alumnado en la Universidad de la Laguna

El Espacio Común Europeo de Educación Superior ha traído consigo cambios sustanciales en los fines y en la forma de organizar la enseñanza, ya que se intenta ahora que sea el alumnado el verdadero protagonista de su proceso formativo y que esta formación tenga una dimensión profesionalizadora. Con ello la función tutorial del profesorado universitario se ha revalorizado debido a su importante contribución como guía de aprendizaje y estimulador del desarrollo integral del alumnado. En este trabajo se define un modelo de actuación y los resultados de una experiencia con la que se potencia desde la tutoría de carrera la adaptación de los estudiantes a la enseñanza universitaria y el desarrollo de las competencias trasferibles para su futuro profesional.The European Higher Education Area brings with it substantial change in the purposes and organization of education. Those changes flow from the recognition of the student as the centre of the learning process, and the pursuing of a training that educate students not only in the academic field but as professionals. All these have supposed the revaluation of the tutorial functions of university teaching, because of its contribution as a guide of learning and animator of the integral development of students. In this article we define a model of performance, and the results of an experience of career tutoring which promoted the adjustment of the students to university education and the development of competences transferable for her professional future