658 research outputs found
Impact of the Euro 2020 championship on the spread of COVID-19
No full textLarge-scale events like the UEFA Euro 2020 football (soccer) championship offer a unique opportunity to quantify the impact of gatherings on the spread of COVID-19, as the number and dates of matches played by participating countries resembles a randomized study. Using Bayesian modeling and the gender imbalance in COVID-19 data, we attribute 840,000 (95% CI: [0.39M, 1.26M]) COVID-19 cases across 12 countries to the championship. The impact depends non-linearly on the initial incidence, the reproduction number R, and the number of matches played. The strongest effects are seen in Scotland and England, where as much as 10,000 primary cases per million inhabitants occur from championship-related gatherings. The average match-induced increase in R was 0.46 [0.18, 0.75] on match days, but important matches caused an increase as large as +3. Altogether, our results provide quantitative insights that help judge and mitigate the impact of large-scale events on pandemic spread
Searches for Neutral Higgs Boson and Interpretations in the MSSM at LEP
No full textThis paper discusses recent publications of the LEP collaborations DELPHI, L3 and OPAL on searches for Higgs bosons motivated by MSSM scenarios as well as their interpretation in the MSSM. With the final publication of the LEP collaborations available or awaited, more and more interpretations in different MSSM models, including both CP conserving and CP violating, become available. Also specialized analyses close open areas in the parameter space. In the same time, better theoretical calculations with an increased maximal mass of the Higgs boson were presented. Both the new scenarios as well as the new theoretical limit on has consequences for the limits from LEP. The searches, the models in which they are interpreted and the implications of the LEP results for future SUSY searches, especially on the limit, are presented here.This paper discusses recent publications of the LEP collaborations DELPHI, L3 and OPAL on searches for Higgs bosons motivated by MSSM scenarios as well as their interpretation in the MSSM. With the final publication of the LEP collaborations available or awaited, more and more interpretations in different MSSM models, including both CP conserving and CP violating, become available. Also specialized analyses close open areas in the parameter space. In the same time, better theoretical calculations with an increased maximal mass of the Higgs boson were presented. Both the new scenarios as well as the new theoretical limit on has consequences for the limits from LEP. The searches, the models in which they are interpreted and the implications of the LEP results for future SUSY searches, especially on the limit, are presented here
Search for CP Violating neutral Higgs bosons in the MSSM at LEP
No full textThe LEP collaborations ALEPH, DELPHI, L3 and OPAL have searched for the neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and show no signicant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs-like event topologies and limits on MSSM benchmark models, including CP-conserving and CP-violating scenarios. Here, the limits on the model parameters of the CP-violating benchmark scenario CPX and derivates of this scenario are shown.The LEP collaborations ALEPH, DELPHI, L3 and OPAL have searched for the neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and show no signicant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs-like event topologies and limits on MSSM benchmark models, including CP-conserving and CP-violating scenarios. Here, the limits on the model parameters of the CP-violating benchmark scenario CPX and derivates of this scenario are shown
Using Advanced Machine Learning Techniques to Study Poorly Modeled Processes in <em>pp</em> Collisions with the ATLAS Detector
No full textIn high energy particle physics, measurements are made to improve and test our models. Some processes are difficult or impossible to model with current capabilities. For some, this means that one would estimate such processes via data-driven techniques or use less-than-ideal modeling during the measurement. The aim of the research presented in this paper is to explore advanced machine learning techniques to deal with hard-to-model or unmodeled processes in analyses using the ATLAS detector. The two tackled problems addressed in this document are hadronically decaying tau-lepton identification and generating a sensitive variable for a WWbb measurement that enhances tW and ttbar interference
Analysis of GEM Properties and Development of a GEM Support Structure for the ILD Time Projection Chamber
No full textIn the concept of the International Large Detector (ILD), developed for the International Linear Collider (ILC) a Time Projection Chamber (TPC) is envisaged as main tracking detector.Such gaseous detectors have to be equipped with amplification devices in order to enlargethe amount of charge, which is set free by ionization caused by traversing charged particles.Micro Pattern Gas Detectors (MPGDs) will be used in the ILD TPC as amplification stage. Inthis thesis, Gas Electron Multipliers (GEMs) – one specific MPGD species – are analyzed concerning various properties. Effective gains and energy resolutions are compared for GEM foilsproduced by different manufacturers. A good understanding of these observables is obtainedby interpretation of the results with the help of geometrical parameters. Height profile measurements of GEM foils have been performed for the first time and the impact of non perfectflat GEMs is analyzed, especially on dE/dx determination and drift field quality. The resultsemphasize the need of a flat installation of GEMs in TPCs. As a consequence, a new mountingdevice has been developed to ensure flatness and to provide a method to cover large readoutareas, as in the ILD TPC, by introducing the least possible amount of dead material into thedetector. The developed structure has been tested in a TPC protoype, taking cosmic muondata. The influence of the mounting on track reconstruction, single point resolution, trackingefficiency and dE/dx measurements is quantified. The developed mounting is applicable in alarge scale TPC, if some design considerations are taken into account
The Airborne Wind Energy Resource Analysis Tool AWERA
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Wind Energ
Simple and statistically sound recommendations for analysing physical theories
No full textAbstract Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at Zenodo
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