Ciencias naturales por indagación en primaria: Breves notas y dos propuestas prototípicas

En este documento se presenta una guía muy breve para elaborar propuestas didácticas en ciencias por indagación en educación primaria; y se dan dos ejemplos prototípicos

The Aligned two-Higgs Doublet model

Topical Workshop on Low Energy Constraints on Extensions of the Standard Model. Kazimierz, POLAND, JUL 23-27, 2009In the two-Higgs-doublet model the alignment of the Yukawa flavour matrices of the two scalar doublets guarantees the absence of tree-level flavour-changing neutral couplings. The resulting fermion-scalar interactions are parameterized in terms of three complex parameters zeta(f), leading to a generic Yukawa structure which contains as particular cases all known specific implementations of the model based on Z(2) symmetries. These three complex parameters are potential new sources of CP violation.This work has been supported in part by the EU Contract MRTN-CT- 2006-035482 (FLAVIAnet), by MICINN, Spain [grants FPA2007-60323 and Consolider-Ingenio 2010 CSD2007-00042 CPAN] and by Generalitat Valenciana (PROMETEO/2008/069). P.T is indebted to the Spanish MICINN for a FPU fellowship

La modelización usando corporeización en la Enseñanza de las Ciencias

En este trabajo proponemos la corporeización como herramienta didáctica para enseñar modelos y conceptos en diferentes conceptos básicos de la física y la química que aparecen a lo largo de cursos generales y específicos de ciencia. Presentamos una propuesta de diez modelizaciones con corporeización de fenómenos a escala microscópica y macroscópica y mostramos los resultados de un análisis cualitativo de un proceso de corporeización según el esquema de trabajo general. Los resultados muestran la sencillez con la que se discuten conceptos aparentemente complejos y cómo se alcanza la comprensión de la idea aceptada científicamente a partir de la propia modelización de los alumnos. Estos resultados muestran además que esta herramienta conecta a los alumnos con una gran diversidad de propiedades del fenómeno.En este trabajo proponemos la corporeización como herramienta didáctica para enseñar modelos y conceptos en diferentes conceptos básicos de la física y la química que aparecen a lo largo de cursos generales y específicos de ciencia. Presentamos una propuesta de diez modelizaciones con corporeización de fenómenos a escala microscópica y macroscópica y mostramos los resultados de un análisis cualitativo de un proceso de corporeización según el esquema de trabajo general. Los resultados muestran la sencillez con la que se discuten conceptos aparentemente complejos y cómo se alcanza la comprensión de la idea aceptada científicamente a partir de la propia modelización de los alumnos. Estos resultados muestran además que esta herramienta conecta a los alumnos con una gran diversidad de propiedades del fenómeno

From continuous to discontinuous transitions in social diffusion

Models of social diffusion reflect processes of how new products, ideas or behaviors are adopted in a population. These models typically lead to a continuous or a discontinuous phase transition of the number of adopters as a function of a control parameter. We explore a simple model of social adoption where the agents can be in two states, either adopters or non-adopters, and can switch between these two states interacting with other agents through a network. The probability of an agent to switch from non-adopter to adopter depends on the number of adopters in her network neighborhood, the adoption threshold $T$ and the adoption coefficient $a$, two parameters defining a Hill function. In contrast, the transition from adopter to non-adopter is spontaneous at a certain rate $\mu$. In a mean-field approach, we derive the governing ordinary differential equations and show that the nature of the transition between the global non-adoption and global adoption regimes depends mostly on the balance between the probability to adopt with one and two adopters. The transition changes from continuous, via a transcritical bifurcation, to discontinuous, via a combination of a saddle-node and a transcritical bifurcation, through a supercritical pitchfork bifurcation. We characterize the full parameter space. Finally, we compare our analytical results with Montecarlo simulations on annealed and quenched degree regular networks, showing a better agreement for the annealed case. Our results show how a simple model is able to capture two seemingly very different types of transitions, i.e., continuous and discontinuous and thus unifies underlying dynamics for different systems. Furthermore the form of the adoption probability used here is based on empirical measurements.Comment: 7 pages, 3 figure

The B -> Xs gamma Rate and CP Asymmetry within the Aligned Two-Higgs-Doublet Model

In the two-Higgs-doublet model the alignment of the Yukawa matrices in flavour space guarantees the absence of flavour-changing neutral currents at tree level, while introducing new sources for CP violation parametrized in a very economical way. This implies potentially large influence in a number of processes, b -> s gamma being a prominent example where rather high experimental and theoretical precision meet. We analyze the CP rate asymmetry in this inclusive decay and determine the resulting constraints on the model parameters. We demonstrate the compatibility with previously obtained limits. Moreover we extend the phenomenological analysis of the branching ratio, and examine the influence of resulting correlations on the like-sign dimuon charge asymmetry in B decays.Comment: 12 pages, 6 figures. Submitted to Phys.Rev.

Yukawa alignment in the two-Higgs-doublet model

5 páginas, 1 tabla.-- PACS numbers: 12.60.Fr, 11.30.Hv, 12.15.Mm, 14.80.CpIn multi-Higgs-doublet models the alignment in flavor space of the relevant Yukawa matrices guarantees the absence of tree-level flavor-changing couplings of the neutral scalar fields. We analyze the consequences of this condition within the two-Higgs-doublet model and show that it leads to a generic Yukawa structure which contains as particular cases all known specific implementations of the model based on Z2 symmetries. All possible freedom in the Yukawa sector gets parametrized in terms of three complex couplings ςf. In spite of having flavor conservation in the neutral scalar couplings, the phases of these three parameters represent potential new sources of CP violation.This work has been supported in part by the EU Contract No. MRTN-CT-2006-035482 (FLAVIAnet), by MICINN, Spain [grants FPA2007-60323 and Consolider-Ingenio 2010 CSD2007-00042 CPAN] and by Generalitat Valenciana (PROMETEO/2008/069).Peer reviewe

Análisis de la enseñanza de la estructura e interacciones de la materia según la física moderna en primero de bachillerato

En este artículo presentamos el análisis de cómo es la enseñanza de la estructura e interacciones de la materia en la asignatura de Física y Química de primero de bachillerato. El objetivo es evaluar si estos contenidos se introducen en su versión más actualizada, en la línea de la física moderna. Para ello, se han analizado distintos libros de texto de esta asignatura a través de un cuestionario y se han hecho entrevistas a profesores que la imparten

Particle Physics in High School: A Diagnose Study

Abstract The science learning process improves when the contents are connected to students' lives. Particle physics has had a great impact in our society in the last years and has changed the theoretical picture about matter fundamental dynamics. Thus, we think that academic contents about matter components and interactions should be updated. With this study we aim to characterize the level of knowledge of high school students about this topic. We built a test with questions about classical atomic models, particle physics, recent discoveries, social implications and students opinions about it. Contrary to our first suspicion, students' answers show a high variability. They have new physics ideas and show a great interest towards modern concepts. We suggest including an updated view of this topic as part of the curriculum

Inquiry-based science education in primary school in Spain : teachers' practices

Teaching science by inquiry allows students to develop scientific skills, which is key during primary school, and enhances learning. In this study we present the results of a survey to 63 primary school teachers in Spain about their practices in science class and their knowledge about inquiry-based science education (IBSE). Our results show that concept-based paradigm of science is predominant. Scientific skills, besides observation, are not developed, and the concept of research is restricted to bibliographic search. Teachers believe that IBSE is feasible in the Spanish educative system, although they identify the length of the curriculum and the lack of time are the main obstacles