Measurement of the Higgs boson properties with Run 2 data collected by the ATLAS experiment

All current measurements of the Higgs boson properties agree very well with the Standard Model predictions. However, theories beyond the Standard Model are needed to explain fundamental open questions. Many of these theories predict deviations in the Higgs sector, in particular in the couplings of the Higgs boson to the elementary particles. These can be tested at the LHC by measuring production and decay rates of the Higgs boson with increasing precision. The measurements are performed in the Simplified Template Cross Section framework, that divides the phase space into production modes and kinematic regions, in order to use shape information in an, as much as possible, model independent approach. This still allows a combination of different decay channels in order to profit from their sensitivities in different phase space regions. The work presented in this documents uses proton-proton collision data recorded at a center-of-mass energy of $\sqrt{s} = 13 TeV$ by the ATLAS detector. Despite a low statistics, the Higgs decay into two photons profits from a very clean experimental signature, an excellent mass resolution and a smooth background. It is therefore an excellent channel to make precision measurements, in particular in phase space regions with high statistics but large background contributions. This thesis presents the Higgs boson mass measurement using 36 fb$^{-1}$ of integrated luminosity, as well as a measurement of its production cross sections using 80 fb$^{-1}$ of data. A crucial ingredient for these measurements is a careful calibration of the photon energy. A complicated calibration chain is applied, correcting for all the possible sources of miscalibration in the detector and the reconstruction. The final step uses the decay of the $Z$ boson into an electron-positron pair as a standard candle. Detailed studies on this step are as well presented in this thesis. Since no concrete hint to a specific new physics model has been found so far, it is important to interprete these measurements in a model independent way. In this work, the combined results in several Higgs decay channels are interpreted in the framework of Effective Field Theories. These results allow to set limits on a complete set of generic operators. The obtained constraints can subsequently be re-interpreted in concrete new physics models

Mesure des propriétés du boson de Higgs avec les donnees du Run 2 collectees par l'experience ATLAS

All current measurements of the Higgs boson properties agree very well with the Standard Model predictions. However, theories beyond the Standard Model are needed to explain fundamental open questions. Many of these theories predict deviations in the Higgs sector, in particular in the couplings of the Higgs boson to the elementary particles. These can be tested at the LHC by measuring production and decay rates of the Higgs boson with increasing precision. The measurements are performed in the Simplified Template Cross Section framework, that divides the phase space into production modes and kinematic regions, in order to use shape information in an as much as possible model independent approach. This still allows a combination of different decay channels in order to profit from their sensitivities in different phase space regions. The work presented in this documents uses proton-proton collision data recorded at a center-of-mass energy of 13TeV by the ATLAS detector.Despite a low statistics, the Higgs decay into two photons profits from a very clean experimental signature, an excellent mass resolution and a smooth background. It is therefore an excellent channel to make precision measurements, in particular in phase space regions with high statistics but large background contributions. This thesis presents the Higgs boson mass measurement using 36ifb of integrated luminosity, as well as a measurement of it production cross sections using 80ifb of data. A crucial ingredient for these measurements is a careful calibration of the photon energy. A complicated calibration chain is applied, correcting for all the possible sources of miscalibration in the detector and the reconstruction. The final step uses the decay of the Z boson into an electron-positron pair as a standard candle. Detailed studies on this step are as well presented in this thesis.Since no concrete hint to a specific new physics model has been found so far, it is important to interprete these measurements in a model independent way. In this work, the combined results in several Higgs decay channels are interpreted in the framework of Effective Field Theories. These results allow to set limits on a complete set of generic operators. The obtained constraints can subsequently be re-interpreted in concrete new physics models.Les mesures actuelles des propriétés du boson de Higgs sont en bon accord avec les prédictions du Modèle Standard. Cependant, des théories au-delà du Modèle Standard sont néssessaires pour expliquer des questions fondamentales toujours ouvertes. Beaucoup de ces théories prédisent des déviations du Modèle Standard dans le secteur du Higgs, en particulier pour les couplages du boson de Higgs aux particules fondamentales. Celles-ci peuvent être testées au LHC dans des mesures des taux de production et de désintégration du boson de Higgs, avec une présision croissante. Ces mesures sont faites dans le contexte des Simplified Template Cross Sections; dans cette approche, l'espace de phase est divisé en modes de production et régions cinématiques, afin d'exploiter l'information de la forme des distributions de la manière la plus générique possible. Ceci permet également une combinaison facile de plusieurs modes de désintégration du boson de Higgs, exploitant ainsi leur différente sensitivité dans différentes régions de l'espace de phase. Le travail présenté dans cette thèse utilise des données de collisions de protons enregistrées à une energie de 13TeV par le détecteur ATLAS.Malgré une faible statistique, la désintégration du boson de Higgs en deux photons profite d'une signature expérimentale très propre, d'une résolution de masse excellente et d'un bruit de fond lisse. Elle représente donc un canal excellent pour les mesures de précision, en particulier dans des régions d'espace de phase avec une grande statistique, mais aussi une large contribution de bruit de fond. Ce document présente la mesure de la masse du boson de Higgs avec 36ifb de luminosité intégrée, ainsi que la mesure de sections efficaces de production avec 80ifb de données. Un ingrédient crucial pour ces mesures est une calibration précise de l'énergie des photons. Une chaine de calibration complexe est appliquée pour corriger toute source possible de biais de calibration dans le détecteur et lors de la réconstruction. L'étape finale utilise la désintégration du boson Z en paire electron-positron comme référence. Des études détaillées de cette étape sont également présentées.Comme aucun indice concret vers un modèle particulier de nouvelle physique a été trouvé jusqu'à maintenant, il est important d'interpréter les mesures de manière générique. Dans cette thèse, les résultats combinés de plusieurs canaux de désintégration du boson de Higgs sont interprétés dans le contexte de théories effectives des champs. Ces résultats permettent de déterminer des limites sur un large ensemble d'opérateurs. Les résultat obtenus peuvent ensuite être interprétés dans des modèles particuliers

Measurement of differential cross sections in Higgs boson decays to bosons using the ATLAS detector

International audienceWith the large $pp$ collision dataset collected by the ATLAS experiment at the Large Hadron Collider at 13 TeV, detailed measurements of Higgs boson production can be performed in decays to bosons. This proceeding presents measurements of differential cross sections in Higgs boson decays to two photons or to four leptons, and a comparison to state-of-the-art theory predictions

Recent results on leptonic and semileptonic BB decays from Belle

International audienceSemileptonic and leptonic B decays are powerful probes to search for physics beyond the Standard Model (SM) as they can be calculated in the SM with high precision. We report recent results on rare B decays with leptons from the Belle experiment at the KEKB e+e collider. The B!Dtn mode is sensitive to New Physics effects such as a charged Higgs or leptoquark current, while the world average of the branching ratio shows a discrepancy from the SM. Recently, Belle has performed a measurement of this mode using t decays to hadronic final states, which is essentially independent of previous measurements from Belle. With this method, the t lepton polarization in B!Dtn has been measured for the first time. Recent results on purely leptonic decay, B! mn will also be discussed. The analyses are based on the full data set of Belle containing 772 million B¯B pairs

Mesure des propriétés du boson de Higgs avec les donnees du Run 2 collectees par l'experience ATLAS

All current measurements of the Higgs boson properties agree very well with the Standard Model predictions. However, theories beyond the Standard Model are needed to explain fundamental open questions. Many of these theories predict deviations in the Higgs sector, in particular in the couplings of the Higgs boson to the elementary particles. These can be tested at the LHC by measuring production and decay rates of the Higgs boson with increasing precision. The measurements are performed in the Simplified Template Cross Section framework, that divides the phase space into production modes and kinematic regions, in order to use shape information in an as much as possible model independent approach. This still allows a combination of different decay channels in order to profit from their sensitivities in different phase space regions. The work presented in this documents uses proton-proton collision data recorded at a center-of-mass energy of 13TeV by the ATLAS detector.Despite a low statistics, the Higgs decay into two photons profits from a very clean experimental signature, an excellent mass resolution and a smooth background. It is therefore an excellent channel to make precision measurements, in particular in phase space regions with high statistics but large background contributions. This thesis presents the Higgs boson mass measurement using 36ifb of integrated luminosity, as well as a measurement of it production cross sections using 80ifb of data. A crucial ingredient for these measurements is a careful calibration of the photon energy. A complicated calibration chain is applied, correcting for all the possible sources of miscalibration in the detector and the reconstruction. The final step uses the decay of the Z boson into an electron-positron pair as a standard candle. Detailed studies on this step are as well presented in this thesis.Since no concrete hint to a specific new physics model has been found so far, it is important to interprete these measurements in a model independent way. In this work, the combined results in several Higgs decay channels are interpreted in the framework of Effective Field Theories. These results allow to set limits on a complete set of generic operators. The obtained constraints can subsequently be re-interpreted in concrete new physics models.Les mesures actuelles des propriétés du boson de Higgs sont en bon accord avec les prédictions du Modèle Standard. Cependant, des théories au-delà du Modèle Standard sont néssessaires pour expliquer des questions fondamentales toujours ouvertes. Beaucoup de ces théories prédisent des déviations du Modèle Standard dans le secteur du Higgs, en particulier pour les couplages du boson de Higgs aux particules fondamentales. Celles-ci peuvent être testées au LHC dans des mesures des taux de production et de désintégration du boson de Higgs, avec une présision croissante. Ces mesures sont faites dans le contexte des Simplified Template Cross Sections; dans cette approche, l'espace de phase est divisé en modes de production et régions cinématiques, afin d'exploiter l'information de la forme des distributions de la manière la plus générique possible. Ceci permet également une combinaison facile de plusieurs modes de désintégration du boson de Higgs, exploitant ainsi leur différente sensitivité dans différentes régions de l'espace de phase. Le travail présenté dans cette thèse utilise des données de collisions de protons enregistrées à une energie de 13TeV par le détecteur ATLAS.Malgré une faible statistique, la désintégration du boson de Higgs en deux photons profite d'une signature expérimentale très propre, d'une résolution de masse excellente et d'un bruit de fond lisse. Elle représente donc un canal excellent pour les mesures de précision, en particulier dans des régions d'espace de phase avec une grande statistique, mais aussi une large contribution de bruit de fond. Ce document présente la mesure de la masse du boson de Higgs avec 36ifb de luminosité intégrée, ainsi que la mesure de sections efficaces de production avec 80ifb de données. Un ingrédient crucial pour ces mesures est une calibration précise de l'énergie des photons. Une chaine de calibration complexe est appliquée pour corriger toute source possible de biais de calibration dans le détecteur et lors de la réconstruction. L'étape finale utilise la désintégration du boson Z en paire electron-positron comme référence. Des études détaillées de cette étape sont également présentées.Comme aucun indice concret vers un modèle particulier de nouvelle physique a été trouvé jusqu'à maintenant, il est important d'interpréter les mesures de manière générique. Dans cette thèse, les résultats combinés de plusieurs canaux de désintégration du boson de Higgs sont interprétés dans le contexte de théories effectives des champs. Ces résultats permettent de déterminer des limites sur un large ensemble d'opérateurs. Les résultat obtenus peuvent ensuite être interprétés dans des modèles particuliers

Electron and photon energy calibration with the ATLAS detector

An accurate calibration of the energy measurement of electron and photon is needed for many ATLAS physics analysis. The calibration of the energy measurement is performed in-situ using a large statistics of Z->ee events. A pre-requisite of this calibration is a good understanding of the material in front of the calorimeter and of the inter-calibration of the different calorimeter layers. The Z->ee sample is also used to measure the energy resolution. The results obtained with the pp collisions data at sqrt(s)=13 TeV in 2016 (2015) corresponding to an integrated luminosity of 33.9 (3.1)fb-1 of sqrt(s)=13 TeV are presented as well as the corresponding uncertainties on the electron and photon energy scales

Analyzing user behavior with Matomo in the online information system Grammis

The grammatical information system grammis combines descriptive texts on German grammar with dictionaries of specific word classes and grammatical terminology. In this paper, we describe the first attempts at analyzing user behavior for an online grammar of the German language and the implementation of an analysis and data extraction tool based on Matomo, a web analytics tool. We focus on the analysis of the keywords the users search for, either within grammis or via an external search platform like Google, and the analysis of the interaction between the text components within grammis and the integrated dictionaries. The overall results show that about 50% of the searches are for grammatical terms, and that the users shift from texts to dictionaries, mainly by using the integrated links to the dictionary of terminology within the texts. Based on these findings, we aim to improve grammis by extending its integrated dictionaries

Das Informationssystem grammis als Ressource für die internationale Germanistik

Grammis ist eine Online-Plattform des Leibniz-Instituts für Deutsche Sprache, die Forschungsergebnisse, Erklärungen und Hintergrundwissen zur deutschen Grammatik präsentiert. Das Angebot zielt einerseits auf linguistische Laien, die sich für grammatische Phänomene interessieren; andererseits auf die Fachöffentlichkeit, indem es aktuelle wissenschaftliche Meilensteine des IDS dokumentiert. Für beide Nutzungsgruppen werden im Beitrag exemplarische Inhalte vorgestellt. Weiterhin sollen erste Ergebnisse einer explorativen Nutzungsstudie sowie jüngere technische Neuerungen vorgestellt werden

Inter-ring communication allows the GroEL chaperonin complex to distinguish between different substrates

The productive folding of substrate proteins by the GroEL complex of Escherichia coli requires the activity of both the chaperonin rings. These heptameric rings were shown to regulate the chaperonins’ affinity for substrates and co-chaperonin via inter-ring communications; however, the molecular details of the interactions are not well understood. We have investigated the effect of substrate binding on inter-ring communications of the chaperonin complex, both the double-ring GroEL as well as the single-ring SR1 chaperonin in complex with four different substrates by using mass spectrometry. This approach shows that whereas SR1 is unable to distinguish between Rubisco, gp23, gp5, and MDH, GroEL shows clear differences upon binding these substrates. The most distinctive binding behavior is observed for Rubisco, which only occupies one GroEL ring. Both bacteriophage capsid proteins (gp23 and gp5) as well as MDH are able to bind to the two GroEL rings simultaneously. Our data suggest that inter-ring communication allows the chaperonin complex to differentiate between substrates. Using collision induced dissociation in the gas phase, differences between the chaperonin(substrate) complexes are observed only when both rings are present. The data indicate that the size of the substrate is an important factor that determines the degree of stabilization of the chaperonin complex

Observation of four top quark production in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceThe observation of the production of four top quarks in proton-proton collisions is reported, based on a data sample collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016-2018 at the CERN LHC and corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with two same-sign, three, or four charged leptons (electrons and muons) and additional jets are analyzed. Compared to previous results in these channels, updated identification techniques for charged leptons and jets originating from the hadronization of b quarks, as well as a revised multivariate analysis strategy to distinguish the signal process from the main backgrounds, lead to an improved expected signal significance of 4.9 standard deviations above the background-only hypothesis. Four top quark production is observed with a significance of 5.6 standard deviations, and its cross section is measured to be 17.7$^{+3.7}_{-3.5}$ (stat) $^{+2.3}_{-1.9}$ (syst) fb, in agreement with the available standard model predictions