B+→K−π+π+B^+\to K^-\pi^+\pi^+: three-body final state interactions and KπK\pi isospin states

Final state interactions are considered to formulate the $B$ meson decay amplitude for the $K\pi\pi$ channel. The Faddeev decomposition of the Bethe-Salpeter equation is used in order to build a relativistic three-body model within the light-front framework. The S-wave scattering amplitude for the $K\pi$ system is considered in the $1/2$ and $3/2$ isospin channels with the set of inhomogeneous integral equations solved perturbatively. In comparison with previous results for the $D$ meson decay in the same channel, one has to consider the different partonic processes, which build the source amplitudes, and the larger absorption to other decay channels appears, that are important features to be addressed. As in the $D$ decay case, the convergence of the rescattering perturbative series is also achieved with two-loop contributions.Comment: 10 pages, 4 figure

Seismic behaviour of vernacular architecture

Vernacular buildings are in several seismic prone regions a relevant part of the building stock. They represent an important part of the of the cultural legacy, and of the technological and heritage context of the society. The present paper presents a revision of the effect of recent earthquake disasters in old buildings, and discusses the influence of the main structural elements in the vulnerability of these buildings, as well as the more common failure mechanisms. Finally, it is presented a review on the elements that more contribute to the seismic behaviour and performance of vernacular buildings.Project ‘SEISMIC-V –Vernacular Seismic Culture in Portugal’ (PTDC/ATP-AQI/3934/2012), from the Portuguese Science and Technology Foundation (FCT

Structural conservation and vernacular construction

Modern societies understand built cultural heritage, including vernacular construction, as a landmark of culture and diversity, which needs to be protected and brought to the next generations in suitable condition. Still, a large part of this heritage is affected by structural problems that menace the safety of buildings and people. In the case of vernacular construction, deterioration due to abandonment is often present, making the phenomena of urbanization one of the most important menaces to this built heritage. The developments in the areas of inspection, non-destructive testing, monitoring and structural analysis of historical constructions, together with recent guidelines for reuse and conservation, allow for safer, economical and adequate remedial measures, as discussed in this paperProject ‘SEISMIC - V – Vernacular Seismic Culture in Portugal’ (PTDC/ATP - AQI/ 3934/2012) , from the Portuguese Science and Technology Foundation (FCT

Avaliação de segurança de estruturas de madeira através de análise probabilística

O presente trabalho apresenta diferentes modelos geométricos e mecânicos na definição de parâmetros probabilísticos de avaliação de segurança para estruturas existentes em madeira, influenciadas por diferentes acções e atendendo a modelos de degradação. O caso de estudo é referente às asnas do Laboratório Chimico, em Coimbra, tendo a avaliação de segurança sido analisada através da técnica de simulação de Monte Carlo

Recent astrophysical observations reproduced by a short-range correlated van der Waals-type model?

We perform an improvement in a van der Waals-type model by including it effects of short-range correlations (SRC). Attractive and repulsive parts of the nucleon-nucleon interaction are assumed to be density-dependent functions, more specifically, we adopt the Carnahan-Starling (CS) method for the latter, and a suitable expression for the former in order to reproduce the structure of the Clausius (C) real gas model. The parametrizations of the resulting model, named as CCS-SRC model, are shown to be capable of reproducing the flow constraint at the high-density regime of symmetric nuclear matter for incompressibility values inside the range of $K_0=(240\pm 20)$ MeV. In the context of stellar matter, our findings point out a good agreement of the CCS-SRC model with recent astrophysical observational data, namely, mass-radius contours and dimensionless tidal deformability regions and values, coming from gravitational waves data related to the GW170817 and GW190425 events, and from the NASA's Neutron star Interior Composition Explorer (NICER) mission. Furthermore, the values for the symmetry energy slope of the model ($L_0$) are in agreement with a recent range found for this quantity, claimed to be consistent with results reported by the updated lead radius experiment (PREX-2) collaboration. In this case, higher values of $L_0$ are favored, while the opposite scenario does not allow simultaneous compatibility between the model and the astrophysical data.Comment: 9 pages, 11 figure