\bar{p}p low energy parameters from annihilation cross section data

The recent experimental data obtained by the OBELIX group on total $\bar{p}p$ annihilation cross section are analysed; the low energy spin averaged parameters of the $\bar{p}p$ scattering amplitude (the imaginary parts of the S-wave scattering length and P-wave scattering volume) are extracted from the data. Their values are found to be equal to $Im a_{sc} = - 0.69 \pm 0.01 (stat) \pm 0.03 (sys) fm, Im A_{sc} = - 0.76 \pm 0.05 (stat) \pm 0.04 (sys) fm^3$. The results are in very good agreement with existing atomic data.Comment: latex.tar.gz file, 8 pages, 1 figur

The Continuum Spectrum of the 4N System. Results and Challenges

The recent calculation of the four nucleon continuum spectrum are reviewed. Faddeev-Yakubovsky equations in configuration space have been solved for the four nucleon system with special interest in their scattering states. We present results concerning the structure of the first $^4$He, scattering states in different (T,S) channels including the first inelatic threshold N+3N$\to$NN+NN and the n-t cross section using realistic potentials.Comment: 9 pages, 8 Figures Contribution to the 16th International IUPAP conference on Few-Body Problems in Physics, Taipei 6-10 march 2000. to be published in Nucl. Phy

Association of personality and disposional mindfulness with work engagement and performance

Treball Final de Grau en Psicologia. Codi: PS1048. Curs: 2018/2019.Mindfulness is becoming more and more important in the work context. Dispositional mindfulness refers to mindfulness as a personality-like trait and it is clearly associated with work-related variables such as work engagement and performance. This construct is also influenced by personality traits and associated with subjective well-being. The main aim of this study was to explore the relationship between dispositional mindfulness, work-related variables, and happiness in workers of an online marketing company. We also examined the association between subjective well-being and workrelated variables. Our hypotheses were: (1) Dispositional mindfulness scores would be related to work engagement and work performance; (2) the five facets of dispositional mindfulness would be associated with work-related variables; (3) the personality dimensions emotional stability and conscientiousness would be associated with workrelated variables; and (4) subjective well-being would correlate with work engagement and performance. Participants were 73 workers from a group of online marketing companies. The questionnaires used measured personality, dispositional mindfulness, work engagement and performance, and subjective well-being. The results partially confirmed the hypotheses. It was found that work-related variables were associated with mindfulness, especially work performance. In addition, the non-judging facet of dispositional mindfulness and the trait conscientiousness were also related to performance. Finally, happiness was significantly correlated with work-related variables. In conclusion, the non-judging facet of mindfulness and the personality trait conscientiousness are relevant factors in the work context, without forgetting the role of happiness.El mindfulness está adquiriendo cada vez más importancia en el ámbito laboral. El mindfulness disposicional hace referencia al mindfulness como rasgo y está claramente relacionado con variables relacionadas con el trabajo, como el compromiso y desempeño laborales. Este constructo, a su vez, puede verse influido por los rasgos de personalidad y se asocia con el bienestar subjetivo. El objetivo de este estudio fue explorar la relación entre el mindfulness disposicional y variables relacionadas con el trabajo, así como la felicidad en una empresa. Nuestras hipótesis fueron: (1) las puntuaciones de la escala del mindnfulness disposicional estarían asociadas con compromiso y desempeño laborales; (2) las cinco facetas del mindfulness se relacionarían con las dos variables del laborales; (3) las dimensiones de estabilidad emocional y responsabilidad se relacionarían con compromiso y desempeño laborales; y, (4) el bienestar subjetivo estaría relacionado con las variables laborales evaluadas.. La muestra estaba compuesta por 73 trabajadores de una empresa de marketing online. Los cuestionarios usados medían la personalidad, mindfulness disposicional, compromiso y desempeño laborales, y bienestar subjetivo. Los resultados que se obtuvieron confirmaron parcialmente las hipótesis planteadas. De este modo, encontramos que las variables laborales estaban asociadas con el mindfulness, siendo con desempeño la relación más alta. Asimismo, solamente una de las facetas del mindfulness, no juzgar, se asoció con desempeño laboral. En cuanto a las dimensiones de personalidad, la responsabilidad fue la que más se relacionó con las variables del trabajo. Finalmente, la felicidad correlacionaba significativamente con las variables asociadas al trabajo. Se concluyó que el mindfulness y la dimensión responsabilidad son factores importantes a tener en cuenta en el contexto laboral, así como los aspectos positivos como el bienestar subjetivo

Solutions of the Wick-Cutkosky model in the Light-Front Dynamics

We study relativistic effects in a system of two scalar particles interacting via a scalar exchange in the Light Front Dynamcis framework. The results are compared to those provided by Bethe-Salpeter and non relativistic equations. It is found in particular that for massive exchange, the relativistic description is of crucial importance even in the limit of zero binding energy. PACS: 11.10, 03.70, 03.65P Keywords: Light-Front Dynamics, Relativistic equations, Quantum Field TheoryComment: 12 pages, 11 figures, Latex.tar.gz file Accepted in Phys. Lett.

Small clusters of fermions

By comparing respectively the interaction between 3He atoms and the neutron-neutron one, we examine the possibility for both fermionic systems to form small clusters.Comment: Contributed talk to 17th International IUPAP Conference on Few-Body Problems in Physics, Durham, North Carolina, 5-10 June 2003. Published in the proceedings (Elsevier, 2004) pp. S106-S10

Ab-initio calculations of four-nucleon elastic scattering

We present microscopic calculations of low energy scattering observables in all possible four nucleon systems : n-3H, p-3He and p-3H. Results were obtained by solving Faddeev-Yakubovski equations in configuration space, appropriately modified to include Coulomb and three-nucleon forces

Complex scaling method for three- and four-body scattering above the break-up thresholds

A formalism based on the complex-scaling method is presented to solve the few particle scattering problem in configuration space using bound state techniques with trivial boundary conditions. Several applications to A=3,4 systems are presented to demonstrate the efficiency of the method in computing elastic as well as break-up reactions with Hamiltonians including both short and long-range interaction.Comment: FB20 conference proceeding