RPV stops bump off the background

We study the 8 TeV LHC reach on pair produced heavy flavored di-jet resonances. Motivated by theories of R-parity violation in supersymmetry we concentrate on a final state with two b-jets and two light jets. We exploit b-tagging to reject the background and discuss its importance at the trigger level to probe light stops. We present kinematical selections that can be used to isolate the signal as a bump in the mass distribution of the candidate resonances. We find that stops with R-parity violating couplings giving rise to fully hadronic final states can be observed in the current run of the LHC. Remarkably, the LHC can probe stop masses well within the range predicted by naturalness.Comment: 9 pages, 1 figure, 1 table; references added, matches the published versio

Light stop squarks and b-tagging

A significant part of the parameter space for light stop squarks still remains unconstrained by collider searches. For both R-Parity Conserving (RPC) and R-Parity Violating (RPV) scenarios there are regions in which the stop mass is around or below the top quark mass that are particularly challenging experimentally. Here we review the status of light stop searches, both in RPC and RPV scenarios. We also propose strategies, generally based on exploiting b-tagging, to cover the unconstrained regions.Comment: To appear in the Proceedings of the Corfu Summer Institute 2014 "School and Workshops on Elementary Particle Physics and Gravity", Corfu, Greec

Spot the stop with a b-tag

The LHC searches for light compressed stop squarks have resulted in considerable bounds in the case where the stop decays to a neutralino and a charm quark. However, in the case where the stop decays to a neutralino, a bottom quark and two fermions via an off-shell W-boson, there is currently a significant unconstrained region in the stop-neutralino mass plane, still allowing for stop masses in the range 90-140 GeV. In this paper we propose a new monojet-like search for light stops, optimized for the four-body decay mode, in which at least one $b$-tagged jet is required. We show that, already by using the existing 8 TeV LHC data set, such a search would cover the entire unconstrained region. Moreover, in the process of validating our tools against an ATLAS monojet search, we show that the existing limit can be extended to exclude also stop masses below 100 GeV.Comment: 6 pages, 1 figure, 2 tables, revtex4 latex style; v2: matches the version published in PRL with the title "Monojetlike Searches for Top Squarks with a b Tag

Theoretical, numerical, and experimental methodologies for structural analysis of polymeric aeronautical elements produced via additive manufacturing

L'abstract è presente nell'allegato / the abstract is in the attachmen

Implementación de una red neuronal tipo perceptrón en GPU

El objetivo de este trabajo de fin de grado es implementar un perceptrón multicapa en la plataforma de computación en GPU de propósito general CUDA, para poder explotar el paralelismo por el que se caracterizan las tarjetas gráficas. Se ha realizado tanto una tarea de formación en el ámbito de las redes neuronales básicas, hasta llegar al perceptrón multicapa, como en el ámbito del lenguaje de programación CUDA, del que se partía desde cero. Así mismo, se ha aprendido a utilizar de forma exitosa la biblioteca cuBLAS, especializada en operaciones matemáticas. Adicionalmente, se ha podido comprobar cómo, con las pruebas realizadas sobre la multiplicación de matrices, operación base del perceptrón multicapa, la diferencia de eficiencia entre una GPU y una CPU utilizando CUDA puede ser hasta 20 veces mayor medida en GFLOPS, mientras que, si utilizamos la biblioteca cuBLAS, obtenemos un rendimiento hasta 1.000 veces mayor.Grado en Ingeniería de Tecnologías de Telecomunicació

From eggs to bites: do ovitrap data provide reliable estimates of Aedes albopictus biting females?

Background. Aedes albopictus is an aggressive invasive mosquito species that represents a serious health concern not only in tropical areas, but also in temperate regions due to its role as vector of arboviruses. Estimates of mosquito biting rates are essential to account for vector-human contact in models aimed to predict the risk of arbovirus autochthonous transmission and outbreaks, as well as nuisance thresholds useful for correct planning of mosquito control interventions. Methods targeting daytime and outdoor biting Ae. albopictus females (e.g., Human Landing Collection, HLC) are expensive and difficult to implement in large scale schemes. Instead, egg-collections by ovitraps are the most widely used routine approach for large-scale monitoring of the species. The aim of this work was to assess whether ovitrap data can be exploited to estimate numbers of adult biting Ae. albopictus females and whether the resulting relationship could be used to build risk models helpful for decision-makers in charge of planning of mosquito-control activities in infested areas. Method. Ovitrap collections and HLCs were carried out in hot-spots of Ae. albopictus abundance in Rome (Italy) along a whole reproductive season. The relationship between the two sets of data was assessed by generalized least square analysis, taking into account meteorological parameters. Result. The mean number of mosquito females/person collected by HLC in 150 (i.e., females/HLC) and the mean number of eggs/day were 18.9 ± 0.7 and 39.0 ± 2.0, respectively. The regression models found a significant positive relationship between the two sets of data and estimated an increase of one biting female/person every five additional eggs found in ovitraps. Both observed and fitted values indicated presence of adults in the absence of eggs in ovitraps. Notably, wide confidence intervals of estimates of biting females based on eggs were observed. The patterns of exotic arbovirus outbreak probability obtained by introducing these estimates in risk models were similar to those based on females/HLC (R0 > 1 in 86% and 40% of sampling dates for Chikungunya and Zika, respectively; R0 < 1 along the entire season for Dengue). Moreover, the model predicted that in this case-study scenario an R0 > 1 for Chikungunya is also to be expected when few/no eggs/day are collected by ovitraps. Discussion. This work provides the first evidence of the possibility to predict mean number of adult biting Ae. albopictus females based on mean number of eggs and to compute the threshold of eggs/ovitrap associated to epidemiological risk of arbovirus transmission in the study area. Overall, however, the large confidence intervals in the model predictions represent a caveat regarding the reliability of monitoring schemes based exclusively on ovitrap collections to estimate numbers of biting females and plan control interventions

Advances in the automatic lemmatization of Old English: class V strong verbs (L-Y)

[EN] The grammatical description of Old English lacks complete and systematic lemmatization, which hinders Natural Language Processing studies in this language, as they strongly rely on the existence of large, annotated corpora. Moreover, the inflectional features of Old English preclude token-based automatic lemmatization. Therefore, specifically goal-oriented applications must be developed to account for the automatic lemmatization of specific variable categories. This article designs an automatic lemmatizer within the framework of Morphological Generation to address the type-based lemmatization of Old English class V strong verbs (L-Y). The lemmatizer is implemented with rules that account for inflectional, derivational and morphophonological variation. The generated forms are compared with the most relevant corpora of Old English for validation before being assigned a lemma. The lemmatizer is successful in supplying form-lemma associations not yet accounted for in the literature, and in identifying mismatches and areas for manual revision.Ministerio de Ciencia e InnovaciónTorre Alonso, R. (2022). Advances in the automatic lemmatization of Old English: class V strong verbs (L-Y). Revista de Lingüística y Lenguas Aplicadas. 17:143-161. https://doi.org/10.4995/rlyla.2022.16132OJS1431611