Performance Studies of Prototype II for the CASTOR forward Calorimeter at the CMS Experiment

We present results of the performance of the second prototype of the CASTOR quartz-tungsten sampling calorimeter, to be installed in the very forward region of the CMS experiment at the LHC. The energy linearity and resolution, as well as the spatial resolution of the prototype to electromagnetic and hadronic showers are studied with E=20-200 GeV electrons, E=20-350 GeV pions, and E=50,150 GeV muons from beam tests carried out at CERN/SPS in 2004. The responses of the calorimeter using two different types of photodetectors (avalanche photodiodes APDs, and photomultiplier tubes PMTs) are compared.Comment: 16 pages, 22 figs., submitted to EPJ-

Preoperative evaluation of cytologically indeterminate thyroid nodules with 18F-FDG PET

Esse artigo tem o objetivo de discutir o papel da tomografia por emissão de pósitrons (PET) com 18F-FDG na avaliação pré-operatória de pacientes com nódulos de tireóide com citologia indeterminada. Para o cálculo da sensibilidade, foram selecionados todos os estudos com pacientes com carcinoma de tireóide. Para o cálculo da especificidade, foram selecionados apenas estudos desenhados para avaliação dos pacientes com nódulos com citologia indeterminada. O achado de captação focal na PET-18F-FDG relacionou-se com a presença de carcinoma de tireóide na maioria dos estudos. A sensibilidade do exame foi bastante alta na detecção de malignidade tireoidiana, porém sua especificidade variou de 0% a 66%, sendo de 39% em estudo brasileiro. Concluindo, os estudos indicam que a PET-18F-FDG pode reduzir o número de tireoidectomias desnecessárias em pacientes com nódulos de tireóide com citologia indeterminada. Entretanto, o percentual relativamente elevado de resultados falso-positivos, o alto custo, a baixa disponibilidade do exame em países em desenvolvimento e a pouca experiência clínica ainda limitam o uso da PET-18F-FDG com essa finalidade.The aim of this article is to discuss the role of 18F-FDG Positron Emission Tomography (PET) in the preoperative evaluation of patients with cytologically indeterminate thyroid nodules. All studies with patients with thyroid cancer were selected to the calculation of sensitivity. Only studies aiming to evaluate patients with thyroid nodules whose cytological result was indeterminate were selected to establish the specificity. The finding of focal 18F-FDG uptake at PET was associated with the presence of thyroid malignancy in most of the studies. The sensitivity of the exam to the detection of thyroid malignancy was extremely high, but the specificity varied from 0 to 66%. In our experience, the specificity was 39%. In conclusion, the studies suggest that 18F-FDG PET can reduce the number of unnecessary thyroidectomies performed in patients with cytologically indeterminate thyroid nodules. However, the relatively high percentage of false positive results, the high costs, the low availability of this exam in developing countries and the low clinical experience still restrict the use of 18F-FDG PET when recommended with this aim

FACET : a new long-lived particle detector in the very forward region of the CMS experiment

We describe a proposal to add a set of very forward detectors to the CMS experiment for the high-luminosity era of the Large Hadron Collider to search for beyond the standard model long-lived particles, such as dark photons, heavy neutral leptons, axion-like particles, and dark Higgs bosons. The proposed subsystem is called FACET for Forward-Aperture CMS ExTension, and will be sensitive to any particles that can penetrate at least 50 m of magnetized iron and decay in an 18 m long, 1 m diameter vacuum pipe. The decay products will be measured in detectors using identical technology to the planned CMS Phase-2 upgrade.Peer reviewe

Yang-Mills Theory In Axial Gauge

The Yang-Mills functional integral is studied in an axial variant of 't Hooft's maximal Abelian gauge. In this gauge Gau\ss ' law can be completely resolved resulting in a description in terms of unconstrained variables. Compared to previous work along this line starting with work of Goldstone and Jackiw one ends up here with half as many integration variables, besides a field living in the Cartan subgroup of the gauge group and in D-1 dimension. The latter is of particular relevance for the infrared behaviour of the theory. Keeping only this variable we calculate the Wilson loop and find an area law.Comment: 43 pages REVTeX, 6 figure

The External Exposome and Allergies: From the Perspective of the Epithelial Barrier Hypothesis

IntroductionIn the last decades, we have seen a rapid increase in the prevalence of allergic diseases such as asthma, allergic rhinitis, atopic dermatitis, and food allergies. The environmental changes caused by industrialization, urbanization and modernization, including dramatic increases in air pollutants such as particulate matter (PM), diesel exhaust, nitrogen dioxide (NO2), ozone (O3), alarming effects of global warming, change and loss of biodiversity, affect both human health and the entire ecosystem.ObjectiveIn this review, we aimed to discuss the effects of the external exposome on epithelial barriers and its relationship with the development of allergic diseases by considering the changes in all stakeholders of the outer exposome together, in the light of the recently proposed epithelial barrier hypothesis.MethodTo reach current, prominent, and comprehensive studies on the subject, PubMed databases were searched. We included the more resounding articles with reliable and strong results.ResultsExposure to altered environmental factors such as increased pollution, microplastics, nanoparticles, tobacco smoke, food emulsifiers, detergents, and household cleaners, and climate change, loss and change in microbial biodiversity, modifications in the consumption of dietary fatty acids, the use of emulsifiers, preservatives and the decrease in the antioxidant content of the widely consumed western diet may disrupt the epithelial barriers of the skin, respiratory and gastrointestinal tracts, making us more vulnerable to exogeneous allergens and microbes. Epithelial cell activation, microbial dysbiosis and bacterial translocation disrupt the immune balance and a chronic Th2 inflammation ensues.ConclusionDramatic increases in air pollution, worrisome effects of global warming, dysbiosis, changing dietary habits and the complex interactions of all these factors affect the epithelial barriers and local and systemic inflammation. We want to draw attention to the emerging health effects of environmental changes and to motivate the public to influence government policies for the well-being of humans and the nature of the earth and the well-being of future generations

Epithelial barrier hypothesis: Effect of the external exposome on the microbiome and epithelial barriers in allergic disease

Environmental exposure plays a major role in the development of allergic diseases. The exposome can be classified into internal (e.g., aging, hormones, and metabolic processes), specific external (e.g., chemical pollutants or lifestyle factors), and general external (e.g., broader socioeconomic and psychological contexts) domains, all of which are interrelated. All the factors we are exposed to, from the moment of conception to death, are part of the external exposome. Several hundreds of thousands of new chemicals have been introduced in modern life without our having a full understanding of their toxic health effects and ways to mitigate these effects. Climate change, air pollution, microplastics, tobacco smoke, changes and loss of biodiversity, alterations in dietary habits, and the microbiome due to modernization, urbanization, and globalization constitute our surrounding environment and external exposome. Some of these factors disrupt the epithelial barriers of the skin and mucosal surfaces, and these disruptions have been linked in the last few decades to the increasing prevalence and severity of allergic and inflammatory diseases such as atopic dermatitis, food allergy, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, and asthma. The epithelial barrier hypothesis provides a mechanistic explanation of how these factors can explain the rapid increase in allergic and autoimmune diseases. In this review, we discuss factors affecting the planet’s health in the context of the ‘epithelial barrier hypothesis,’ including climate change, pollution, changes and loss of biodiversity, and emphasize the changes in the external exposome in the last few decades and their effects on allergic diseases. In addition, the roles of increased dietary fatty acid consumption and environmental substances (detergents, airborne pollen, ozone, microplastics, nanoparticles, and tobacco) affecting epithelial barriers are discussed. Considering the emerging data from recent studies, we suggest stringent governmental regulations, global policy adjustments, patient education, and the establishment of individualized control measures to mitigate environmental threats and decrease allergic disease

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum