Unitarization effects in EFT predictions of WZ scattering at the LHC

Effective field theories are an incredibly powerful tool in order to study and understand the true nature of the symmetry breaking sector dynamics of the Standard Model. However, they can suffer from some theoretical problems such as that of unitarity violation. Nevertheless, in order to interpret experimental data correctly a fully unitary prescription is needed. To this purpose, unitarization methods are addressed, but each of them leads to a different (unitary) prediction. Because of this, there is an inherent theoretical uncertainty in the determination of the effective field theory parameters due to the choice of one unitarization scheme. In this work, we quantify this uncertainty assuming a strongly interacting electroweak symmetry breaking sector, described by the effective electroweak chiral Lagrangian. We focus on the bosonic part of this effective Lagrangian and choose in particular the WZ scattering as our main VBS channel to study the sensitivity to new physics at the LHC. We study the different predictions of various well known unitarization methods, considering the full coupled system of helicity amplitudes, and construct the 95\% confidence level exclusion regions for the most relevant electroweak chiral Lagrangian parameters, given by the two anomalous quartic gauge couplings $a_4$ and $a_5$. This provides a consistent analysis of the different constraints on EChL parameters that can be achieved by using different unitarization methods in a combined way.Comment: 25 pages, 8 figures (20 plots), this version matches the published article in Phys. Rev.

Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment

A quantitative study of the neutron environment in the Canfranc Underground Laboratory has been performed. The analysis is based on a complete set of simulations and, particularly, it is focused on the IGEX-DM dark matter experiment. The simulations are compared to the IGEX-DM low energy data obtained with different shielding conditions. The results of the study allow us to conclude, with respect to the IGEX-DM background, that the main neutron population, coming from radioactivity from the surrounding rock, is practically eliminated after the implementation of a suitable neutron shielding. The remaining neutron background (muon-induced neutrons in the shielding and in the rock) is substantially below the present background level thanks to the muon veto system. In addition, the present analysis gives us a further insight on the effect of neutrons in other current and future experiments at the Canfranc Underground Laboratory. The comparison of simulations with the body of data available has allowed to set the flux of neutrons from radioactivity of the Canfranc rock, (3.82 +- 0.44) x 10^{-6} cm^{-2} s^{-1}, as well as the flux of muon-induced neutrons in the rock, (1.73 +- 0.22(stat) \+- 0.69(syst)) x 10^{-9} cm^{-2} s^{-1}, or the rate of neutron production by muons in the lead shielding, (4.8 +- 0.6 (stat) +- 1.9 (syst)) x 10^{-9} cm^{-3} s^{-1}.Comment: 17 pages, 8 figures, elsart document class; final version to appear in Astroparticle Physic

Concentración de inmigrantes y mercado inmobiliario en la ciudad de Barcelona

Diferentes autores mantienen que el sistema de precio de suelo y vivienda existente es un factor que perpetúa la segregación residencial y la desigualdad, situación que se agrava cuando se refiere a algunos grupos de inmigrantes que terminan alojándose en espacios degradados con características por debajo de las mínimas legales de habitabilidad (CORTÉS, 2000; MUSTERD, 2003). Se parte de la hipótesis que la población inmigrante del municipio de Barcelona, se ubica principalmente en esas zonas de menor calidad de vivienda y, que estas zonas de concentración de inmigrantes y menor calidad coinciden con las viviendas de menor precio. Se construyó el Índice de Calidad (iQviv) y el Índice de Características (iCviv) de viviendas. Observando su relación con el Índice de Concentración de Inmigrantes y la evolución del valor de la vivienda 2004-2010 en Barcelona se constató que no siempre las zonas con menor índice de calidad de vivienda y donde se concentran los inmigrantes coincide con las que presentan los precios inmobiliarios más bajos. El mercado inmobiliario es un factor determinante de la estructura socio-espacial de la ciudad, a través del cual se puede modificar el modelo de ciudad que se desea alcanzar respecto a la concentración de colectivos y segregación social. La estrategia residencial gubernamental (localización, régimen de tenencias, diversidad de usos) debe orientar las ciudades hacia la mixtura socio-espacial, la convivencia y el desarrollo social. Y tener mayor incidencia sobre el mercado residencial a fin de evitar una sobrevaloración de la vivienda y especulación de la misma aprovechándose de la necesidad y posibilidades de acceso a la vivienda reducidas de la población más desfavorecida.Different authors have linked the existing land and housing price system as a factor that perpetuates residential segregation and inequality, this situation is exacerbated when it comes to some immigrant groups that end in degraded areas with characteristics below the minimum legal for habitability (CORTÉS, 2000; MUSTERD, 2003). The hypothesis is that immigrant population of Barcelona city is located primarily in those areas of lower quality housing and that this immigrants concentration areas with lower quality housing index matches with the lower housing prices. On this research it was made the Housing Quality Index (iQviv), and the Housing Characteristics Index (iCviv), and it was observed their correlation with the Immigrant Concentration Index (ICI) and the evolution of the Housing Value from 2004-2010, in Barcelona. Observing that the areas with lower housing quality index and where immigrants are concentrated not always matches with the areas that have the lower real estate prices. The housing market is a determinant factor of the social-spatial structure of the city, through which it can be changed the city model to be achieved related with concentration of groups and social segregation. The government residential strategy (in terms of location, tenure arrangements, diversity of uses) should guide the city towards socio-spatial mix, coexistence, and social development of the population. Also it should have a greater impact on the residential market in order to avoid housing speculation and overvaluation, instead of taking advantage of the immigrant population needs, and therefore reducing their possibilities of housing access to.Peer Reviewe

Using Wavelets to reject background in Dark Matter experiments

A method based on wavelet techniques has been developed and applied to background rejection in the data of the IGEX dark matter experiment. The method is presented and described in some detail to show how it efficiently rejects events coming from noise and microphonism through a mathematical inspection of their recorded pulse shape. The result of the application of the method to the last data of IGEX is presented.Comment: 14 pages, 8 figures. Submitted to Astrop. Phy

Analysis of the performance of a hybrid CPU/GPU 1D2D coupled model for real flood cases

Coupled 1D2D models emerged as an efficient solution for a two-dimensional (2D) representation of the floodplain combined with a fast one-dimensional (1D) schematization of the main channel. At the same time, high-performance computing (HPC) has appeared as an efficient tool for model acceleration. In this work, a previously validated 1D2D Central Processing Unit (CPU) model is combined with an HPC technique for fast and accurate flood simulation. Due to the speed of 1D schemes, a hybrid CPU/GPU model that runs the 1D main channel on CPU and accelerates the 2D floodplain with a Graphics Processing Unit (GPU) is presented. Since the data transfer between sub-domains and devices (CPU/GPU) may be the main potential drawback of this architecture, the test cases are selected to carry out a careful time analysis. The results reveal the speed-up dependency on the 2D mesh, the event to be solved and the 1D discretization of the main channel. Additionally, special attention must be paid to the time step size computation shared between sub-models. In spite of the use of a hybrid CPU/GPU implementation, high speed-ups are accomplished in some cases

The Neogene Savannas of North America : A Retrospective Analysis on Artiodactyl Faunas

Savanna-like ecosystems were present at high latitudes in North America during much of the Neogene. Present-day African savannas, like the Serengeti, have been proposed to be modern analogs of these paleosavannas, particularly those from the middle Miocene of the Great Plains region of the United States. Both these extant and extinct savannas contain a preponderance of artiodactyl (even-toed ungulate) species; however, the taxonomic composition of each fauna is different. While present-day African savannas are dominated by ruminants (primarily bovids), the Neogene savannas of North America were dominated by a diversity of both camelid and non-bovid ruminant families. This study provides a quantitative test of the similarity of the artiodactyl faunas of the North American Neogene paleosavannas to those of the modern-day African savannas. A correspondence analysis of ecomorphological features revealed considerable overlap between modern and fossil faunas. The morphospace occupation of the extinct North American ruminants falls within that of the African bovids. Some of the extinct camelids also fall within this same morphospace, but many do not, perhaps indicating an environmental difference such as greater aridity in Neogene North America. The diversity and disparity of artiodactyl faunas through the Neogene of North America changed along with changing temperatures and precipitation regimes. The taxonomic and ecomorphological diversity of the Serengeti ruminant fauna is statistically comparable to those North American paleofaunas occurring during or immediately after the Middle Miocene Climatic Optimum (MMCO), but the later, more depauperate faunas are no longer comparable. This study quantitatively analyzes artiodactyl communities as they changed with the cooling and drying trend seen during the Neogene.Peer reviewe