Structure of the Vacuum in Deformed Supersymmetric Chiral Models

We analyze the vacuum structure of N=1/2 chiral supersymmetric theories in deformed superspace. In particular we study O'Raifeartaigh models with C-deformed superpotentials and canonical and non-canonical deformed Kahler potentials. We find conditions under which the vacuum configurations are affected by the deformations.Comment: 15 pages, minor corrections. Version to appear in JHE

Variables predictors of the set in the defence complex in volleyball

El objetivo de la investigación fue conocer las variables predictoras de la eficacia de colocación en el complejo de defensa (KII), en ambos géneros, en categorías de formación. La muestra del estudio estuvo compuesta por 2.404 acciones de juego, 1.104 en género masculino y 1.300 en género femenino, desarrolladas por los 34 equipos participantes en el Campeonato de España Under 16. La variable dependiente fue la eficacia de colocación. Las variables independientes se agruparon en: variables de defensa, de colocación en KII y de bloqueo. Los resultados determinaron que, en ambos géneros, la eficacia de defensa, la técnica de colocación y la participación en bloqueo predecían la eficacia de la colocación; en género masculino, zona de defensa y tiempo de colocación; ninguna variable fue predictora únicamente en género femenino. Esta información puede ser relevante para el desarrollo del proceso de entrenamiento en voleibolThe objective of the research was to analyse the variables predictors of the setting efficacy in the defence complex (KII), in youth athlete, in both genders. The study sample was comprised of 2404 game actions, 1104 in the male gender and 1300 in the female gender. The actions were carried out by the 34 teams that participated in the Spanish Under-16 Championship. The dependant variable was the setting efficacy. The results determined that, in both genders, the dig efficacy, setting technique and the participation in block predicted the setting efficacy; in male gender, the defence zone and tempo of set; no predictor variables were exclusive to the female gender. This information may be relevant when developing training processes in volleyballEste estudio se ha realizado gracias a la aportación de la Consejería de Economía e Infraestructuras de la Junta de Extremadura a través del Fondo Europeo de Desarrollo Regiona

Searching for tidal tails around ω\omega Centauri using RR Lyrae Stars

We present a survey for RR Lyrae stars in an area of 50 deg$^2$ around the globular cluster $\omega$ Centauri, aimed to detect debris material from the alleged progenitor galaxy of the cluster. We detected 48 RR Lyrae stars of which only 11 have been previously reported. Ten among the eleven previously known stars were found inside the tidal radius of the cluster. The rest were located outside the tidal radius up to distances of $\sim 6$ degrees from the center of the cluster. Several of those stars are located at distances similar to that of $\omega$ Centauri. We investigated the probability that those stars may have been stripped off the cluster by studying their properties (mean periods), calculating the expected halo/thick disk population of RR Lyrae stars in this part of the sky, analyzing the radial velocity of a sub-sample of the RR Lyrae stars, and finally, studying the probable orbits of this sub-sample around the Galaxy. None of these investigations support the scenario that there is significant tidal debris around $\omega$ Centauri, confirming previous studies in the region. It is puzzling that tidal debris have been found elsewhere but not near the cluster itself.Comment: 11 pages, 11 figures, Accepte

Close encounters involving RAVE stars beyond the 47 Tucanae tidal radius

The most accurate 6D phase-space information from the Radial Velocity Experiment (RAVE) was used to integrate the orbits of 105 stars around the galactic globular cluster 47 Tucanae, to look for close encounters between them in the past, with a minimum distance approach less than the cluster tidal radius. The stars are currently over the distance range 3.0 kpc $<$ d $<$ 5.5 kpc. Using the uncertainties in the current position and velocity vector for both, star and cluster, 105 pairs of star-cluster orbits were generated in a Monte Carlo numerical scheme, integrated over 2 Gyr and considering an axisymmetric and non-axisymmetric Milky-Way-like Galactic potential, respectively. In this scheme, we identified 20 potential cluster members that had close encounters with the globular cluster 47 Tucanae, all of which have a relative velocity distribution (V$_{rel}$) less than 200 km s$^{-1}$ at the minimum distance approach. Among these potential members, 9 had close encounters with the cluster with velocities less than the escape velocity of 47 Tucanae, therefore a scenario of tidal stripping seems likely. These stars have been classified with a 93\% confidence level, leading to the identification of extratidal cluster stars. For the other 11 stars, V$_{rel}$ exceeds the escape velocity of the cluster, therefore they were likely ejected or are unassociated interlopers.Comment: 10 pages, 6 figures, 2 table, Accepted for publication in MNRA

Comparative analysis of the serve in volleyball between the spanish championships 2005-2010

El objetivo fue analizar los cambios que ha experimentado el saque desde el Campeonato de España cadete masculino de 2005 al de 2010. Mediante la observación sistemática se analizaron 1594 acciones, en las cuales se midieron las siguientes variables: zona de origen, eficacia, tipo de saque, zona de recepción, función del receptor, dirección y temporalidad. Los resultados reflejaron que en los últimos años, el saque realizado por jugadores de categoría de formación ha sufrido modificaciones relevantes, tales como, mejora de la eficacia, incremento del empleo del saque en salto, y realización del saque con un carácter más táctico. Pese a la mayor aproximación del saque a los perfiles existentes en alto nivel, se recomienda que el saque de voleibol en categorías de formación se entrene en función de las características y nivel de los jugadores, evitando el mimetismo de lo que acontece en alto nivelThe aim of this research was to analyze the changes in the characteristics of the serve between the male Under-16 Spanish Championships that took place in 2005 and 2010. Through systematic observation 1594 actions were analyzed. The measured variables were: serve zone, effectiveness, serve type, reception zone, in-game role of the receptor, serve direction and timing. The results showed that in recent years, the serve performed by players at training stages has undergone significant changes, such as improved efficiency, increased use of jump serve, and execution of the serve with a more tactical role. Despite of the closest approach of the serve to the existing high level profiles, it is recommended to train the serve in volleyball training stages according to the characteristics and level of players, avoiding mimicry of what happens at a high levelEste trabajo ha sido realizado gracias al apoyo del Programa de Formación de Personal Investigador (FPI) de la Consejería de Empleo, Empresa e Innovación del Gobierno de Extremadura (España), y gracias al Ministerio de Ciencia e Innovación en el Plan Nacional de I+D+I 2008-2011 (ref. DEP2011-27503