Accuracy versus precision in boosted top tagging with the ATLAS detector

Abstract The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as top tagging, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider. Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied. This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at √ s = 13 TeV. The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study. The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance. To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available.</jats:p

Estudo da prevalência de fluorose dentária em Aracaju Study of the prevalence of dental fluorosis in Aracaju

Com o objetivo de determinar a prevalência de fluorose dentária em Aracaju (SE), 196 escolares foram submetidos a exame clínico bucal, utilizando o índice de Dean. Pôde ser concluído que a prevalência de fluorose dentária em escolares de cinco a quinze anos do município de Aracaju (SE) foi de 8,16%, não implicando risco à saúde pública. Porém, estudos semelhantes devem ser realizados com periodicidade regular, além de orientação aos órgãos responsáveis pela fluoretação da água, para que os níveis considerados ótimos para essa região sejam respeitados, prevenindo assim o surgimento de tal ocorrência.<br>With the aims of determining the prevalence dental fluorosis in the city of Aracaju, Sergipe State, 196 students were submitted to an oral exam, utilizing the Dean's index. It was concluded that the prevalence of dental fluorosis in students ranging from 5 to 15 years old in the city of Aracaju, Sergipe State was of 8.16%, not implying in a risk to public health. However, similar studies must be done regularly, besides orientation to governmental departments responsible for water fluoridation, so that the level considered excellent for this area can be respected, avoiding such problem to occur