Thèses sur le sujet « Final state model »
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1
Norman, Matthew. « Search for non-standard model signatures in the WZ/ZZ final state at CDF Run II ». Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3355835.
Texte intégralRésumé :
Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed July 2, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 149-150).
2
Reinsch, Andreas, et Andreas Reinsch. « Search for Colorful Quantum Black Holes Decaying to an Electron-Jet Final State with the ATLAS Experiment ». Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12370.
Texte intégralRésumé :
A search for quantum black holes with color charge decaying to one electron and
one quark has been performed using data collected by the ATLAS Experiment at
the Large Hadron Collider corresponding to 2.29 fb−1. No excess over the expected
Standard Model interactions has been observed. Limits are set on the production
cross section for events with one electron and one jet resulting from new physical
phenomena. Models with a combined invariant mass of the electron and jet larger
than or equal to 2.5TeV and a cross section above 2.6 fb are excluded at the 95%
confidence level. This allows the exclusion of a significant part of the parameter
space of quantum black hole models.
3
MANZONI, RICCARDO ANDREA. « Search for the Standard Model Higgs boson decaying into a di-$\tau$ pair in the double hadronic final state ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2014. http://hdl.handle.net/10281/55495.
Texte intégralRésumé :
Nel modello standard (SM), le masse dei fermioni sono generate attraverso gli accoppiamenti di Yukawa tra i campi di Higgs e fermionico. La misura di questi accoppiamenti e' fondamentale per corroborare la natura del bosone con massa intorno a 125 GeV scoperto dalle Collaborazioni ATLAS e CMS nel 2012. Il canale tautau e' particolarmente promettente, grazie al branching ratio relativamente alto e alla contenuta contaminazione da parte dei processi di fondo. In questa tesi vengono riportati i risultati della ricerca di un bosone di Higgs SM nello stato finale comprendente due leptoni tau. Sono stati analizzati gli interi dataset di collisioni p-p raccolti da CMS nel 2011 e nel 2012, corrispondenti alla luminosita' di 4.9 fb-1 a sqrt(s)=7 TeV e 19.7 fb-1 a sqrt(s)=8 TeV. Sono stati studiati tutti i sei possibili stati finali di-tau: mutau, etau, tautau, emu, mumu e ee. Questa tesi, in particolare, descrive l'analisi condotta nello stato finale doppio adronico tautau. Nei dati e' stato osservato un eccesso di eventi rispetto alla predizione per i soli fondi. La significanza locale eccede le 3 deviazioni standard per valori di mH compresi tra 115 e 130 GeV. Il prodotto della sezione d'urto per branching ratio, misurato per il segnale a mH=125 GeV, corrisponde a 0.78+/-0.27 volte il valore predetto dallo SM. Questo costituisce l'evidenza dei decadimenti in coppie di leptoni tau del bosone di Higgs a 125 GeV. Nello SM, la massa del bosone di Higgs non è protetta da divergenze date dalle correzioni a loop e la cancellazione di queste divergenze avviene tramite il cosiddetto fine tuning. In modelli oltre lo SM, ad esempio il Minimal Supersymmetric Standard Model (MSSM), la cancellazione avviene in maniera naturale grazie all'introduzione di un bosone (fermione) per ogni fermione (bosone) presente nello SM. In questa tesi viene anche descritta la ricerca di un bosone di Higgs neutro MSSM nel canale tautau. Questo canale e' particolarmente interessante poiche' i decadimenti in tau sono favoriti in buona parte dello spazio dei parametri. Non viene osservato nessun eccesso e si procede quindi a fissare limiti di esclusione nello spazio dei parametri di diversi benchmark scenarios. Vengono inoltre forniti limiti sul prodotto di sezione d'urto per branching ratio per i due piu' rilevanti modi di produzione, gluon-gluon fusion e produzione associata con b-quark.
4
Wehrmeyer, Lara. « Influence of Active Musculature & ; Parameters of the Final Pre-Crash State on the Occupant Response ». Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277117.
Texte intégralRésumé :
Collision avoidance systems have become an integrated part of modern vehicles and aim to avoid accidents or mitigate the crash severity for the occupant. For example, the autonomous emergency braking system influences the pre-crash state of the occupant in sitting posture, stress state, or velocity. The occupant might try to retain its posture by activating muscles, which induce muscle bracing and could counteract the movement of the occupant in the pre-crash phase. Therefore, it is essential to study the influence of active musculature on occupant response in pre-crash and crash events. A finite element human body model (HBM) with and without closed-loop muscle activation control was used to simulate the occupant response during those events. Comparing the HBM responses & head kinematics reveal an influence of muscle bracing in the evasive braking manoeuvre. Simulating the pre-crash and in-crash phase in two stages can provide multiple benefits. However, the correlation between a single-stage simulation (baseline) and a two-stage simulation needs to be investigated. The baseline simulation uses an active HBM to model an occupant during an evasive braking manoeuvre and the muscles are deactivated when entering the frontal impact phase. The parameters of the final pre-crash state, which are needed to mimic the baseline’s response when transitioning from the pre-crash to the in-crash event are investigated in this study. For that reason, sitting position, stress state and velocity are transferred respectively to the initial passive in-crash HBM state. The simulations enabled the comparison of occupant response and calculation of cross-correlation. Each retainment strategy gave a good cross-correlation with the baseline simulation.Kollisionsundvikande system har blivit en viktig del i moderna fordon där syftet är att undvika olyckor samt att minska allvarhetsgraden av olyckor för de åkande. Ett exempel är nödbromssystem som kan påverka den åkandes initiala tillstånd direkt före en krock som, till exempel, sittposition, spänningstillstånd, eller initial hastighet inför krock. Den åkande kan försöka att bibehålla sin hållning genom att aktivera sina muskler vilket påverkar rörelsen av dess kropp under för-krocks fasen. Det är därför viktigt att studera hur aktiva muskler påverkar rörelsen av kroppen hos den åkande under både före krocksfasen och själva krockfasen. En finit element humanmodell (HBM) med och utan reglerad muskelaktivitet används för att prediktera responsen hos den åkande i båda faserna. En jämförelse mellan simuleringarna visar att aktiva muskler kan påverka åkandekinematiken under bromsningsförloppet. Att simulera fasen före krock och fasen under krock i två steg kan medföra flera fördelar. Korrelationen mellan en enkelstegssimulering (originalsimulering) och en tvåstegssimulering måste dock studeras. Som originalsimulering används en aktiv HBM för att modellera den åkande under för-krocksfasen där den reglerade muskelaktiviteten inaktiveras under krockfasen. I denna studie undersöks den åkandes initiala tillstånd före krocken som behövs för att efterlikna originalsimulerings respons vid övergången från för-krocksfasen till krockfasen. Av den anledningen mappas det passiva HBM-tillståndet till det slutliga tillståndet av före krocksfasen för sittposition, spänningstillstånd respektive hastighet. Simuleringarna möjliggjorde en jämförelse av åkande respons och beräkning av korskorrelation. Varje mappningsstrategi gav en bra korskorrelation med originalsimuleringen.
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Hsu, Shih-Chieh. « A study of the standard model Higgs, WW and ZZ production in dilepton plus missing transverse energy final state at CDF Run II ». Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3307688.
Texte intégralRésumé :
Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed August 13, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 197-200).
6
Friedrich, Felix. « Search for neutral Higgs bosons decaying into the leptonic-hadronic di-tau final state in the Minimal Supersymmetric Standard Model with the ATLAS detector ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230294.
Texte intégralRésumé :
A search for the neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model (MSSM) is presented. The analysis is performed on data from proton-proton collisions at a centre-of-mass energy of sqrt{s}=8 TeV at the Large Hadron Collider recorded by the ATLAS detector. The data were collected in 2012, correspond to an integrated luminosity of 20.3 fb-1 and represent the full 8 TeV dataset. This search is performed in the tau-tau final state, with one tau lepton decaying leptonically and the other hadronically. The analysis is optimized in three categories, addressing low-mass Higgs bosons which are accompanied by a bottom quark induced jet or not and high-mass Higgs bosons. No deviations from Standard Model predictions are observed, and therefore no evidences of new Higgs bosons are found. Exclusion limits are set on the cross-section times branching fraction of the Higgs bosons and for parameters m_A and tan{beta} of MSSM benchmark scenariosIn dieser Arbeit wird die Suche nach neutralen Higgs-Bosonen im Rahmen des Minimalen Supersymmetrischen Standardmodells (MSSM) vorgestellt. Die Analyse basiert auf dem kompletten Datensatz von Proton-Proton-Kollisionen des Large Hadron Colliders, LHC, die mit dem ATLAS-Detektor bei einer Schwerpunktsenergie von sqrt{s}=8 TeV im Jahr 2012 aufgenommen wurden. Die Daten entsprechen einer Luminosität 20.3 fb-1. Die Suche fokussiert auf den Tau-Tau Endzustand, wobei ein Tau-Lepton hadronisch zerfällt und das andere leptonisch, entweder in ein Elektron oder in ein Muon. Die Analyse wurde in drei Kategorien optimiert, um sowohl für Higgs-Bosonen im niedrigen Massenbereich von 90-200 GeV als auch im hohen Massenbereich von 200 GeV bis 1 TeV sensitiv zu sein. Der niedrige Massenbereich wurde dabei in zwei Unterkategorien geteilt, entsprechend der Anwesenheit bzw. Abwesenheit von zusätzlichen, durch b-Quarks induzierten Jets, um die Empfindlichkeit für spezielle Higgs-Boson-Produktionsmodi zu erhöhen. Im Rahmen dieser Analyse wurden keine Hinweise auf neue Higgs-Bosonen gefunden und daher Ausschlussgrenzen auf den Wirkungsquerschnitt x Verzweigungsverhältnis gesetzt. Ebenfalls wurden die Resultate in MSSM-Benchmark-Szenarien interpretiert
7
Becker, Sebastian. « Estimation of standard model backgrounds to the search for electroweak production of supersymmetry in events with at least two tau leptons in the final state ». Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-162539.
Texte intégralRésumé :
This thesis presents a search for Supersymmetry in events with at least two hadronically decaying tau leptons and missing transverse energy. The ana\-lysis is focused on the electro-weak production of gaugino pairs. Electroweak production processes for SUSY particles are promising candidates for the discovery of Supersymmetry with $R$-parity conservation at hadron-hadron colliders.
For the analysis a sample of proton-proton collisions at a center of mass energy of $\sqrt{s}=\unit[8]{TeV}$ with an integrated luminosity of $\int {\cal L}~\mathrm{dt}= \unit[20.3]{fb^{-1}}$ is used. The collisions have been recorded with the ATLAS detector at the LHC in the year 2012.
In two different selections the Standard Model predictions are compared with the observations. The observation of 6 events in the first selection and 14 in the second does not deviate significantly from the Standard Model with an expectation of 11 events in the first selection and 17 in the second.
These results are interpreted in a phenomenological Minimal Supersymmetric Standard Model and in simplified models. For a simplified model with a chargino-neutralino pair production scenario the parameter space for masses of the lightest neutralino up to $\unit[100]{GeV}$ and up to $\unit[350]{GeV}$ for the lightest chargino mass can be excluded.
For a simplified model with chargino pair production processes the parameter space for the lightest neutralino mass up to $30-\unit[50]{GeV}$ in a range for the lightest chargino mass of $170-\unit[330]{GeV}$ can be excluded.
This thesis is focused on the estimation techniques of Standard Model background processes. Different methods for the estimation of the background originating from $Z$-boson and top-quark decays are investigated.In dieser Arbeit wird eine Suche nach Supersymmetrie für Ereignisse mit zwei hadronisch zerfallenden Tau Leptonen und fehlender Transversalenergie im Endzustand präsentiert. Die Analyse konzentriert sich dabei auf die elektroschwache Produktion von Gaugino Paaren. Elektroschwache Produktions\-prozesse sind vielversprechende Kandidaten für die Entdeckung der Supersymmetrie mit $R$-Paritätserhaltung an Hadron-Hadron Teilchenbeschleuni\-gern. Für die Analyse wurde ein Datensatz von Proton-Proton Kollisionen bei einer Schwerpunktenergie von $\sqrt{s}=\unit[8]{TeV}$ mit einer integrierten Luminosität von $\int {\cal L}~\mathrm{dt}= \unit[20.3]{fb^{-1}}$ verwendet. Die Daten wurden mit dem ATLAS Detektor am LHC im Jahr 2012 aufgezeichnet. Die beobachteten Datenereignisse wurden mit den Vorhersagen des Standardmodells für zwei unterschiedliche Sätze von Signalauswahlkriterien verglichen. Die Beobachtung von 6 Ereignissen in der ersten Signalregion und 14 Ereignissen in der zweiten weicht nicht signifikant von den Vorhersagen des Standardmodells mit 11 Ereignissen in der ersten Signalregion und 17 in der zweiten ab. Diese Ergebnisse wurden mit Hinblick auf ein phänomenologisches minimal supersymmetrisches Standardmodell und auf vereinfachte supersymmetrische Modelle interpretiert. Für ein vereinfachtes Modell mit Chargino-Neutralino Paarproduktion kann der Parameterraum für Massen des leichtesten Neutralinos bis zu $\unit[100]{GeV}$ und bis zu $\unit[350]{GeV}$ für die Masse des leichtesten Charginos ausgeschlossen werden. Für ein vereinfachtes Mo\-dell mit Chargino Paarproduktion kann der Parameterraum für die leichteste Neutralinomasse bis zu $30-\unit[50]{GeV}$ in einem Bereich der leichtesten Chargino Masse von $170-\unit[330]{GeV}$ ausgeschlossen werden. Das Hauptaugenmerk dieser Arbeit liegt jedoch auf den Verfahren, die zur Bestimmung des Standardmodell-Untergrundes benutzt werden. Unterschiedliche Methoden zur Bestimmung des Untergrunds aus $Z$-Boson und Top-Quark Zerfallsprozessen wurden untersucht.
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Wiglesworth, Craig. « The annealing of SCT silicon microstrip sensors and the search for the Standard Model Higgs Boson in the Four Muon Final State in the ATLAS Detector ». Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539600.
Texte intégral
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Regnard, Simon. « Measurements of Higgs boson properties in the four-lepton final state at sqrt(s) = 13 TeV with the CMS experiment at the LHC ». Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX081/document.
Texte intégralRésumé :
Cette thèse présente une étude de la production de boson de Higgs dans les collisions proton-proton à sqrt(s) = 13 TeV enregistrées avec le détecteur CMS au Grand collisionneur de hadrons (LHC) du CERN, exploitant la voie de désintégration en une paire de bosons Z qui se désintègrent à leur tour en paires d’électrons ou de muons (H->ZZ->4l, l = e,mu).Ce travail s’inscrit dans le contexte du début du Run II du LHC, une nouvelle période de prise de données qui a commencé en 2015 après une interruption de deux ans. Ce redémarrage est marqué par une augmentation de l’énergie dans le centre de masse de 8 TeV à 13 TeV et un resserrement de l’espacement entre paquets de protons de 50 ns à 25 ns. Ces nouveaux paramètres augmentent à la fois la luminosité et placent des contraintes inédites sur le déclenchement, la reconstruction et l’analyse des données de collisions pp. Un effort important est donc consacré à l’amélioration et la réoptimisation du système de déclenchement de CMS pour le Run II, en mettant l’accent sur la reconstruction et la sélection des électrons et sur la préparation de chemins de déclenchement multi-leptons préservant une efficacité maximale pour le canal H->ZZ->4l.Dans un second temps, les algorithmes de sélection hors-ligne des électrons et des muons sont optimisés et leurs efficacités sont mesurées dans les données, tandis que la logique de sélection des candidats à quatre leptons est améliorée. Afin d’extraire des modes de production rares du boson de Higgs tels que la fusion de bosons vecteurs, la production par « Higgsstrahlung » VH et la production associée ttH, une nouvelle répartition des événements sélectionnés en catégories exclusives est introduite, fondée sur des discriminants utilisant le calcul d’éléments de matrice et l’étiquetage de saveur des jets.Les résultats de l’analyse des premières données à 13 TeV sont présentés pour des lots de données enregistrés en 2015 et au début de 2016, qui correspondent à des luminosités intégrées respectives de 2.8 fb-1 and 12.9 fb-1. Le boson de Higgs est redécouvert de façon indépendante à la nouvelle énergie. L’intensité du signal relative à la prédiction du modèle standard, la masse et la largeur de désintégration du boson sont mesurées, ainsi qu’un jeu de paramètres contrôlant les contributions des principaux modes de production attendus. Tous les résultats sont en bon accord avec les prévisions du modèle standard pour un boson de Higgs à 125 GeV, aux incertitudes de mesure près, ces dernières étant dominées par la composante statistique avec l’échantillon de données actuel. Enfin, une autre résonance se désintégrant en quatre leptons est recherchée à haute masse, et aucun excès significatif n’est observéThis thesis reports a study of Higgs boson production in proton-proton collisions at sqrt(s) = 13 TeV recorded with the CMS detector at the CERN Large Hadron Collider (LHC), exploiting the decay channel into a pair of Z bosons that in turn decay into pairs of electrons or muons (H->ZZ->4l, l = e,mu).This work is carried out in the context of the beginning of Run II of the LHC, a new data-taking period that started in 2015, following a two-year-long shutdown. This restart is marked by an increase of the centre-of-mass energy from 8 TeV to 13 TeV, and a narrowing of the spacing of proton bunches from 50 ns to 25 ns. These new parameters both increase the luminosity and set new constraints on the triggering, reconstruction and analysis of pp collision events. Therefore, considerable effort is devoted to the improvement and reoptimization of the CMS trigger system for Run II, focusing on the reconstruction and selection of electrons and on the preparation of multilepton trigger paths that preserve a maximal efficiency for the H->ZZ->4l channel.Secondly, the offline algorithms for electron and muon selection are optimized and their efficiencies are measured in data, while the selection logic of four-lepton candidates is improved. In order to extract rare production modes of the Higgs boson such as vector boson fusion, VH associated production and ttH associated production, a new classification of selected events into exclusive categories is introduced, using discriminants based on matrix-element calculations and jet flavour tagging.Results of the analysis of first 13 TeV data are presented for two data sets recorded in 2015 and early 2016, corresponding to integrated luminosities of 2.8 fb-1 and 12.9 fb-1, respectively. A standalone rediscovery of the Higgs boson in the four-lepton channel is achieved at the new energy. The signal strength relative to the standard model prediction, the mass and decay width of the boson, and a set of parameters describing the contributions of its main predicted production modes are measured. All results are in good agreement with standard model expectations for a 125 GeV Higgs boson within the incertainties, which are dominated by their statistical component with the current data set. Finally, a search for an additional high-mass resonance decaying to four leptons is performed, and no significant excess is observed
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Benato, Lisa. « Search for heavy resonances decaying into a $Z$ boson and a vector boson in the $\nu \bar{\nu}$ $q\bar{q}$ final state at CMS ». Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3426686.
Texte intégralRésumé :
This thesis presents a search for potential signals of new heavy resonances decaying into a pair of vector bosons, with masses between 1 TeV and 4 TeV, predicted by beyond standard model theories. The signals probed are spin-1 W', predicted by the Heavy Vector Triplet model, and spin-2 bulk gravitons, predicted by warped extra-dimension models. The scrutinized data are produced by LHC proton-proton collisions at a center-of-mass energy $\sqrt{s}=13$ TeV during the 2016 operations, and collected by the CMS experiment, corresponding to an integrated luminosity of 35.9 fbinv. One of the boson should be a Z, and it is identified through its invisible decay into neutrinos, while the other electroweak boson, consisting either into a W or into a Z boson, is required to decay hadronically into a pair of quarks. The decay products of heavy resonances are produced with large Lorentz boosts; as a consequence, the decay products of the bosons (quarks and neutrinos) are expected to be highly energetic and collimated. The couple of neutrinos, escaping undetected, is reconstructed as missing momentum in the transverse plane of the CMS detector. The couple of quarks is reconstructed as one large-cone jet, with high transverse momentum, recoiling against the couple of neutrinos. Grooming algorithms are adopted in order to improve the jet mass resolution, by removing soft radiation components and spectator events from the particles clustered as the large-cone jet. The groomed jet mass is used to tag the hadronically decaying vector boson, to define the signal region of the search (close to the nominal mass of the W and Z bosons, between 65-105 GeV) and a signal-depleted control region, that is used for the background estimation. An hybrid data-simulation approach predicts the normalization and the shape of the main background, represented by a vector boson produced in association with jets, by taking advantage of the distribution of data in the signal-depleted control regions. Secondary backgrounds are predicted from simulations. Jet substructure techniques are exploited, in order to classify events into two exclusive purity categories, by distinguishing the couple of quarks inside the large-cone jet. This approach improves the background rejection and the discovery reach. The search is performed by scanning the distribution of the reconstructed mass of the resonance, looking for a local excess in data with regards to the prediction. Depending on the mass, upper limits on the cross-section of heavy spin-1 and spin-2 narrow resonances, multiplied by the branching fraction of the resonance decaying into Z and a W boson for a spin-1 signal, and into a pair of Z bosons for spin-2, are set in the range $0.9$ -- $63$ fb and in the range $0.5$ -- $40$ fb respectively. A W' hypothesis is excluded up to 3.11 TeV, in the Heavy Vector Triplet benchmark A scenario, and up to 3.41 TeV, considering the benchmark B scenario. A bulk graviton hypothesis, given the curvature parameter of the extra-dimension $\tilde{k}=1.0$, is excluded up to 1.14 TeV.Questa tesi presenta una ricerca di potenziali segnali di nuove risonanze pesanti, che decadono in una coppia di bosoni vettori, con masse comprese tra 1 TeV e 4 TeV, predette da teorie oltre il modello standard. I segnali indagati sono W' di spin 1, predette dal modello Heavy Vector Triplet, e gravitoni di spin 2, predetti da modelli che prevedono extra dimensioni ripiegate. I dati esaminati sono prodotti dalle collisioni protone-protone di LHC ad un'energia del centro di massa di $\sqrt{s}=13$ TeV durante le operazioni del 2016, e raccolti dall'esperimento CMS, per una luminosità integrata di 35.9 fbinv. Uno dei bosoni dev'essere una Z, che viene identificata dal suo decadimento invisibile in neutrini, mentre l'altro bosone elettrodebole, sia una W che una Z, deve decadere nel canale adronico in una coppia di quark. I prodotti di decadimento di risonanze pesanti sono generati con significativi boost di Lorentz; di conseguenza, ci si aspetta che i prodotti di decadimento dei bosoni (i quark e i neutrini) abbiano elevate energie e siano collimati. La coppia di neutrini, che sfugge alla rivelazione, viene ricostruita come momento mancante nel piano trasverso del rivelatore CMS. La coppia di quark viene ricostruita come un jet a largo cono, con elevato momento trasverso, che rincula contro la coppia di neutrini. Algoritmi di grooming sono impiegati per migliorare la risoluzione della massa del jet, rimuovendo la radiazione soffice e gli eventi spettatori dalle particelle clusterizzate come jet a largo cono. La massa ripulita del jet viene utilizzata per identificare il bosone vettore che decade in adroni, per definire la regione di segnale della ricerca (vicina alla massa nominale dei bosoni W e Z, nell'intervallo 65-105 GeV) e una regione di controllo svuotata dal segnale, che viene utilizzata per la stima dei fondi. Un approccio ibdrido dati-simulazione predice la normalizzazione e la forma del fondo principale, rappresentato da un bosone vettore prodotto in associazione con jet, sfruttando la distribuzione dei dati nelle regioni di controllo svuotate dal segnale. I fondi secondari sono predetti completamente con le simulazioni. Tecniche di sottostruttura del jet sono adoperate per classificare gli eventi in due categorie esclusive di purezza, distinguendo le coppie di quark dentro al jet a largo cono. Questo approccio migliora la soppressione del fondo e la potenzialità di scoperta. La ricerca viene fatta scansionando la distribuzione della massa ricostruita della risonanza, cercando un eccesso locale nei dati rispetto alle predizioni. In funzione della massa, limiti superiori sulla sezione d'urto per risonanze pesanti e strette di spin 1 e spin 2, moltiplicate per il rapporto di diramazione della risonanza che decade in Z e W per il segnale di spin 1, e in una coppia di bosoni Z per lo spin 2, sono fissati nell'intervallo $0.9$ -- $63$ fb e nell'intervallo $0.5$ -- $40$ fb rispettivamente. Un'ipotesi di W' e' esclusa fino ad una massa di 3.11 TeV, nello scenario A di riferimento dell'Heavy Vector Triplet, e fino a 3.41 TeV, nello scenario B di riferimento. Un'ipotesi di gravitone, dato il parametro di curvatura della dimensione addizionale $\tilde{k}=1.0$, è esclusa fino ad una massa di 1.14 TeV.
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Kraus, Jana [Verfasser]. « W -> ; tau nu(tau) Cross Section Measurement and Search for the Standard Model Higgs Boson in the tau(lep) tau(had) Final State with the ATLAS Detector / Jana Kraus ». Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/1077289677/34.
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Becker, Sebastian [Verfasser], et Dorothee [Akademischer Betreuer] Schaile. « Estimation of standard model backgrounds to the search for electroweak production of supersymmetry in events with at least two tau leptons in the final state / Sebastian Becker. Betreuer : Dorothee Schaile ». München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/1044532319/34.
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Venturi, Manuela [Verfasser], et Karl [Akademischer Betreuer] Jakobs. « Search for the Standard Model Higgs boson in the H → W^+ W^− → ℓ^+ ν ℓ^− ν̄ final state with the ATLAS experiment and study of its spin and parity quantum numbers ». Freiburg : Universität, 2016. http://d-nb.info/1119806003/34.
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Bicker, Karl Alexander [Verfasser], Stephan [Akademischer Betreuer] [Gutachter] Paul et Allen C. [Gutachter] Caldwell. « Model Selection for and Partial-Wave Analysis of a Five-Pion Final State at the COMPASS Experiment at CERN / Karl Alexander Bicker. Betreuer : Stephan Paul. Gutachter : Stephan Paul ; Allen C. Caldwell ». München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1113182229/34.
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Ferreira, de Lima Danilo Enoque. « Top-antitop cross section measurement as a function of the jet multiplicity in the final state and beyond the Standard Model top-antitop resonances search at the ATLAS detector at CERN ». Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5015/.
Texte intégralRésumé :
The top quark is the heaviest particle in the Standard Model, with a strong coupling to the Higgs boson. It is often seen as a window to new physics, therefore understanding its production is a key ingredient for testing the Standard Model or physics Beyond the Standard Model. In this document, the production cross section of top-antitop pairs in its semileptonic decay channel is measured as a function of the jet multiplicity in the ATLAS experiment, using proton-proton collisions at the center-of-mass energy of sqrt(s) = 7 TeV. The top-antitop production with extra jets is the main background for many analyses, including the top-antitop-Higgs production studies. The analysis performed is extended in a search for Beyond the Standard Model physics which predicts a resonance decaying in a top-antitop pair, using ATLAS data at center-of-mass energy of sqrt(s) = 7 TeV. The latter analysis is repeated for ATLAS data collected with sqrt(s) = 8 TeV. Performance studies of b-tagging algorithms in the ATLAS Trigger System are also presented.
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Ruiz, Alvarez José David. « Search for a vector-like quark T' decaying into top+Higgs in single production mode in full hadronic final state using CMS data collected at 8 TeV ». Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10180.
Texte intégralRésumé :
Le LHC (Large Hadron Collider) a produit en 2012 des collisions proton proton à une énergie de 8 TeV dans le centre de masse pour les expériences ATLAS et CMS. Ces deux expériences ont été conçues pour découvrir le boson de Higgs et pour rechercher de nouvelles particules prédites par des modèles théoriques. Le boson de Higgs a été découvert le 4 juillet 2012 par les expériences ATLAS et CMS. Cette découverte marque le début d'une nouvelle période de recherche dans le domaine. Avec la confirmation de l'existence du boson de Higgs, les recherches de nouvelle physique liées à ce boson sont devenues prioritaires. Par exemple, on peut chercher dans les données une nouvelle particule massive qui peut se désintégrer dans un boson de Higgs associé à d'autres particules du modèle standard. Une signature attendue est un boson de Higgs avec un quark top, les deux particules les plus lourdes du modèle standard. Le modèle standard prédit une section efficace pour la production du Higgs avec un quark top. Ainsi une mesure de cette section efficace montrant une valeur plus importante prouverait l'existence de physique au-delà du modèle standard. En outre, l'existence de physique au-delà le modèle standard pourrait montrer des résonances qui se désintègrent dans un quark top et un boson de Higgs. Dans la première partie de ce manuscrit, je présente les bases théoriques et expérimentales du modèle standard, ainsi que le dispositif expérimental. Dans le même chapitre théorique je discute une extension du modèle standard dans le cadre d'un modèle effectif englobant ce dernier. De plus, je détaille une étude de faisabilité d'une recherche d'une des nouvelles particules prédites par ce modèle, un quark vectoriel. Dans la deuxième partie, la recherche dans CMS de ce quark vectoriel T_, partenaire du quark top, est décrite. Ce partenaire du top est une nouvelle particule très similaire au quark top du modèle standard, mais beaucoup plus lourde. On considère le cas où ce nouveau quark se désintègre préférentiellement dans un quark top et un boson de Higgs. J'ai fait cette recherche dans le canal hadronique ou le Higgs se désintègre en deux quarks b et le quark top se désintègre en trois quarks, un quark b et deux quarks légers. J'ai reconstruit la masse du T_ à partir de l'identification de tous ses produits de désintégration. Le résultat obtenu est décrit sous forme des limites observées sur la section efficace de production du T_ déduites à partir de cette analyseDuring 2012, the Large Hadron Collider (LHC) has delivered proton-proton collisions at 8 TeV center of mass energy to the ATLAS and CMS experiments. These two experiments have been designed to discover the Higgs boson and to search for new particles predicted by several theoretical models, as supersymmetry. The Higgs boson has been discovered by ATLAS and CMS experiments on July, 4th of 2012, starting a new era of discoveries in particle physics domain. With the confirmation of the existence of the Higgs boson, searches for new physics involving this boson are of major interest. In particular, data can be used to look for new massive particles that decay into the Higgs boson accompanied with other particles of the standard model. One expected signature is a Higgs boson produced with a top quark, the two heaviest particles in the standard model. The standard model predicts a cross section of top-Higgs production, then any enhancement of their associated production will be a clear signature of physics beyond the standard model. In addition, the existence of physics beyond the standard model can also be reflected by resonances that decay into a top-quark and a Higgs boson. In the first part of my work I describe the theoretical and experimental foundations of the standard model, as well as the experimental device. In the same theoretical chapter, I also discuss the formulation of an extension of the standard model. In addition, I describe a feasibility study of a search of one of the particles predicted by such model. The second part contains the realization of the search for a top partner, T_, within the CMS experiment. This top partner is a new particle very similar to the standard model top quark, but much heavier, that can decay into a top quark and a Higgs boson. The analysis looks for this particle in the full hadronic final state, where the Higgs boson decays into two b-quarks and the top quark decays into three standard model quarks, a b and two light quarks. In this channel, I reconstruct its mass from the identification of all its decay products. As a result of the analysis, I show the limits on the T_ production cross section from the number of observed events in the specific signature
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Friedrich, Felix [Verfasser], Arno [Akademischer Betreuer] [Gutachter] Straessner et Stefania [Gutachter] Xella. « Search for neutral Higgs bosons decaying into the leptonic-hadronic di-tau final state in the Minimal Supersymmetric Standard Model with the ATLAS detector / Felix Friedrich ; Gutachter : Arno Straessner, Stefania Xella ; Betreuer : Arno Straessner ». Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://d-nb.info/1144297591/34.
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Friedrich, Felix [Verfasser], Arno [Akademischer Betreuer] Straessner et Stefania [Gutachter] Xella. « Search for neutral Higgs bosons decaying into the leptonic-hadronic di-tau final state in the Minimal Supersymmetric Standard Model with the ATLAS detector / Felix Friedrich ; Gutachter : Arno Straessner, Stefania Xella ; Betreuer : Arno Straessner ». Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230294.
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Betti, Alessandra [Verfasser]. « Search for the Standard Model Higgs boson pair production and new physics phenomena in the bb τ+hadτ-had final state with the ATLAS detector / Alessandra Betti ». Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/1202848303/34.
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Schillo, Christian [Verfasser], et Markus [Akademischer Betreuer] Schumacher. « Search for the Standard Model Higgs Boson and Test of CP Invariance in Vector-Boson Fusion Production of the Higgs Boson in the Fully Leptonic H->tautau->ll4nu Final State in Proton-Proton Collisions with the ATLAS Detector at the LHC ». Freiburg : Universität, 2016. http://d-nb.info/1122831048/34.
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Ruthmann, Nils [Verfasser], et Karl [Akademischer Betreuer] Jakobs. « Search for standard model H->tau+tau- decays in the Lepton-Hadron final state in proton-proton collisions with the ATLAS detector at the LHC = Suche nach Standardmodell H->tau^+tau^- Zerfällen im Lepton-Hadron Endzustand in Proton-Proton Kollisionen mit dem ATLAS Detektor am LHC ». Freiburg : Universität, 2014. http://d-nb.info/1123482071/34.
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Vaheid, Halimeh. « Generation and Validation of di-Higgs events in the 4τ final state ». Thesis, Uppsala universitet, Högenergifysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355744.
Texte intégralRésumé :
The Higgs self-coupling has a vital role by giving a deeper understanding of the Higgs particle. Furthermore, the way it opens to physics beyond the SM, encourages us to do MC simulationstudies for varying λ_hhh . In this project, we investigate the effects of choosing different values for λ_hhh on the kinematics of all particles involved in the hh → τ τ τ τ decay channel and the resultsare compared with what we get from the SM prediction of λ_hhh .The data show that λ_hhh more close to the SM trilinear Higgs self-coupling results in generatingthe Higgs particles with the higher masses and higher momenta. On the other hand, for the moremassive Higgs bosons we have more energetic neutrinos in the final states which escape from thedetector without being detected.
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Ucchielli, Giulia <1990>. « Study of multi-lepton final states with the ATLAS experiment : from Standard Model to Beyond Standard Model Higgs ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8594/1/ucchielli_giulia_tesi.pdf.
Texte intégralRésumé :
This thesis exploits the features of final states containing light leptons with
same electric charge, produced in LHC proton-proton collisions at 13 TeV and collected by the ATLAS detector during the 2015 and 2016 data-taking.
Events containing leptons with same electric charge allow to reject a
substantial fraction of the background from the Standard Model processes.
New physics is searched both indirectly and directly through two processes:
the production of a Higgs boson in association with a pair of top quarks
(ttH) and the production of new doubly charged Higgs bosons (H++). The
measurement of the ttH signal strength (mu) into leptonic final states provides
mu = 2.5 (+1.3 - 1.1), compatible at 95% confidence level with the Standard Model
prediction mu(ttH) = 1. Regarding direct searches, no evidence for new physics
is found in the search for H++ boson production: lower limits on its mass
are set and vary from 770 GeV to 870 GeV at 95% confidence level.
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Lord, William B., Thomas R. McGuire et Mary G. Wallace. « Efficient and Equitable Solution of Indian Reserved Rights : Final Report ». Water Resources Research Center, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/306469.
Texte intégralRésumé :
Final Report, Efficient and Equitable Solution of Indian Reserved Rights, USGS Grant #14-08-0001-G1320, June 21, 1989.The water rights claims of many Indian reservations in the West are now under adjudication. Frequently, the parties to these adjudications acknowledge that their interests may be better served through negotiated settlements, but they lack comprehensive means for determining mutually acceptable solutions to the conflicts. The research conducted under the title of "Efficient and Equitable Solution of Indian Reserved Rights" (Project #14-08-0001-G1320) sought to 1) develop a conceptual basis for determining Indian water rights; 2) develop an analytical procedure to provide the information needed to resolve water rights conflicts; and 3) apply this analytical procedure to a test case involving the Gila River Basin in Arizona. The methodological core of the research is a set of linked models, encompassing historical, hydrologic, economic, psychological, and institutional elements of the conflict. Hydrologic, institutional, and economic analyses of conjunctive management of surface and groundwater supplies were facilitated by the use of MODSIM, a network optimization model. Data from the model enabled the investigators to construct an impact matrix, defining the effect of each possible settlement option on the goals of the parties. The preferences of the parties were elicited through social judgement analysis. Twelve settlement options were defined on the basis of knowledge of other negotiated settlements, and a final option, representing possible outcomes should the negotiation process fail, was included in the analysis. The next step was to model the possible choices available the contending parties, utilizing an n-person cooperative game framework. This analysis indicated that a set of three settlement options dominated the adjudication option for all players. Each of these included the provision of imported water in lieu of water currently being used in the basin. It is anticipated that the results of this research will be developed as a book-length manuscript by the principal investigators and the research team.
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Sciandra, Andrea [Verfasser]. « Probing the Standard Model of particle physics with ttH, WWZ and WZZ multilepton final states / Andrea Sciandra ». Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/120447964X/34.
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Donkers, Michael A. « Study of photonic final states in e+e- collisions at center of mass energy of 161 and 172 GeV using the OPAL detector at LEP ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ27047.pdf.
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Zhang, Bin. « Searching for Short Range Correlations Using (e,e'NN) Reactions ». Washington, D.C : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Energy Research ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2003. http://www.osti.gov/servlets/purl/824928-2353Al/native/.
Texte intégralRésumé :
Thesis; Thesis information not provided; 1 Feb 2003.Published through the Information Bridge: DOE Scientific and Technical Information. "JLAB-PHY-03-38" "DOE/ER/40150-2762" Bin Zhang. 02/01/2003. Report is also available in paper and microfiche from NTIS.
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Delabat, Díaz Yasiel. « Search for Standard Model Higgs bosons produced in association with top-quark pairs in ttH multilepton final states using the ATLAS detector at the LHC ». Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22550.
Texte intégralRésumé :
Diese Arbeit beschreibt die Suche nach assoziierter Produktion eines Higgsbosons und eines Top-Quark Paares in Proton-Proton Kollisionen bei einer Schwerpunktsenergie von 13 TeV. Für diese Analyse wurden Ereignisse analysiert, die exakt zwei Leptonen mit gleichem Ladungsvorzeichen oder exakt drei Leptonen enthalten und daher auf die Higgs Zerfallsmoden in H->WW, H->ZZ und H->tautau sensitiv sind. Die Daten wurden mit dem ATLAS Detektor am Large Hadron Collider (LHC) in den Jahren 2015-17 aufgezeichnet. Der grösste Untergrund in beiden Kanälen stammt aus assoziierter Produktion von Vektorbosonen mit einem Top-Quark Paar (ttW und tt(Z/gamma)), Dibosonproduktion und Ereignisse, die Photonen und Hadronen, die fehlerhaft als Leptonen identifiziert wurden, erhalten oder Leptonen, die aus Zerfällen von Hadronen stammen. Der Leptonuntergrund wurde mit einer neuen Methode abgeschätzt, die auf separaten Kategorien für jeden Produktionsmodus des Leptonuntergrundes basiert. Der Beitrag jeder Kategorie wird in verschiedenen Kontrollregionen aus dem Vergleich von Daten mit der Simulation bestimmt. Das Verhältnis des gemessenen ttH Wirkungsquerschnitts zu der Vorhersage des Standardmodells und die Normierungsfaktoren des Untergrundes werden gleichzeitig in einem Profile-Likelihood-Fit bestimmt. Das Verhältnis des gemessenen zum erwarteten ttH Wirkungsquerschnitts, unter der Annahme einer Higgsbosonmasse von 125 GeV, wurde zu 0.88(+0.54/-0.51) mit einer beobachteten (erwarteten) Signifikanz von 1.80 (2.52) Standardabweichungen gemessen. Das entspricht einem geschätzten Wirkungsquerschnitt für die ttH Produktion von 446(+241/-227) fb, in Übereinstimmung mit der Standardmodellvorhersage von 507(+35/-50) fb.This thesis describes the search for the associated production of a Higgs boson and a top-quark pair in proton-proton collisions with a center-of-mass energy of 13 TeV. The analysis focuses on events containing two leptons with same-sing electric charge or exactly three leptons in the final state. With these requirements, the analysis is sensitive to the H->WW, H->ZZ and H->tautau Higgs decay modes. The used data was recorded with the ATLAS detector at the Large Hadron Collider (LHC) during the 2015-17 period. The primary sources of background were found to be ttW, tt(Z/gamma), Diboson processes and events containing fake or non-prompt leptons coming from hadron decays, photon conversions and electron charge mis-identification. The estimation of the hadron decay and photon conversion fake backgrounds was performed using a novel semi-data driven technique where Monte Carlo background categories are created for each fake process of interest. A profile likelihood fit to data is then used to extract a normalization factor for each fake category, which are used to correct the Monte Carlo predictions. The ratio of the measured ttH signal cross-section to the Standard Model expectations and a normalization factor for the ttW process are extracted simultaneously from the same fit. The measured to expected cross-section ratio for a Standard Model Higgs boson of mass 125 GeV was found to be 0.88(+0.54/-0.51) with an observed (expected) significance of 1.80 (2.52) standard deviations. This corresponds to an estimated ttH cross-section of 446(+241/-227) fb, in agreement with the Standard Model prediction of 507(+35/-50) fb.
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MILESI, MARCO. « SEARCH FOR THE STANDARD MODEL HIGGS BOSON PRODUCED IN ASSOCIATION WITH TOP QUARK PAIRS IN MULTI-LEPTONIC FINAL STATES WITH THE ATLAS DETECTOR AT THE LHC ». Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/579521.
Texte intégralRésumé :
The search for the Standard Model (SM) Higgs boson produced in asso- ciation with top quarks - known as ttH production - plays a crucial role in the Large Hadron Collider (LHC) physics programme, as it allows a direct measurement of the Higgs field Yukawa coupling to the heaviest fermion and can constrain effects of new physics beyond the Standard Model in the top coupling sector.
This thesis presents a search for the ttH production in an inclusive mul- tileptonic final state, with a proton-proton collision dataset corresponding to an integrated luminosity of Int( L dt ) = 36.1 fb−1, collected by the ATLAS experiment at the LHC in 2015 and 2016 at a centre-of-mass energy √s=13TeV.
The final state is characterised by high jet multiplicity, and the presence of several electrons and muons, as well as hadronically decaying tau leptons. The multiplicity of these physics objects allows the definition of several categories to enhance the sensitivity of the analysis.
The particular focus of my work lies on the final state where exactly two light leptons with the same electric charge and no hadronic taus are found - indicated as 2l SS 0τhad - for which I developed a novel technique to estimate the reducible background of non-prompt (fake) electrons and muons.
Boosted decision tree algorithms are trained to discriminate the ttH signal events from the two major background processes in this channel: ttV (V=W,Z) and events with fake leptons. A fit of our model to the observed data is performed, and the results are interpreted using a frequentist approach. A best-fit value for the strength of the ttH production cross section with respect to the Standard Model expectation of μ = 1.5+0.7 is observed.
The observed sensitivity of this search corresponds to a 2.7σ excess of events above the SM background-only hypothesis, with an expected median sensitivity of 1.9σ for a model where the SM ttH production is assumed.
Combination with the other categories of the ttH to multi-leptons analysis eventually leads to a signal strength of μ = 1.6+0.5, with an observed (expected) sensitivity of 4.1σ (2.8σ) above the SM background-only hypothesis.
This indicates the strongest evidence to date for the ttH production mode. Furthermore, I present a study on improvements to the ATLAS track re- construction algorithm to enhance its performance in environments with high density of tracks, such as the core of boosted hadronic jets and hadronically decaying tau leptons.
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Li, Dikai. « Search for the standard model Higgs boson in ℓν + b¯b final states in 9. 7 fb−1 of p¯p collisions with the DØ detector ». Paris 6, 2013. http://www.theses.fr/2013PA066775.
Texte intégralRésumé :
In this manuscript, I have presented the search for the Higgs boson in the WH→ℓνb¯b at the D0 experiment, and my contributions to it. This is the most sensitive channel for low mass Higgs boson studies, and it is combined with ZH channels to search for H→b¯b decays, first at D0, then, in combination with the equivalent channels analyzed by the CDF collaborations. These are then further combined with the other Higgs boson analysis channels of the Tevatron. Since a good agreement between data and simulation is obtained, and no signal excess is observed in data, upper observed (expected) limits (for MH = 125 GeV) are set at 95%confidence level on the ratio of the WH cross section multiplied by the branching ratio of H→b¯b to its Standard Model prediction, which represent 4. 8 (4. 7) times the Standard Model expectation. This procedure is performed using a semi-frequentist approach in order to efficiently take into account systematic uncertainties, which are found to degrade the sensitivity by about 20% once taken into account and after minimizing their impact by constraining them to data. The result presented in this thesis, based on an integrated luminosity of 9. 7 fb−1 has been originally published in Physics Review Letter in September 2012, and with some small modifications in Physics Review D in September 2013. It is included in the D0 and in the Tevatron combination. The results of the H→b¯b searches were validated through a measurement of the diboson (WZ+ZZ) production cross sectionDans ce manuscrit, j'ai présenté la recherche du boson de Higgs dans le WH→ℓ νb¯b à l'expérience D0, et mes contributions à elle. C'est la voie la plus sensible pour les études boson de Higgs de faible masse, et il est combiné avec les chaînes ZH pour rechercher H→b¯b se désintègre, d'abord à D0, puis, en combinaison avec les chaînes équivalentes analysés par les collaborations CDF. Ce sont ensuite combinés avec les autres canaux d'analyse de Higgs boson du Tevatron. Depuis un bon accord entre les données et la simulation est obtenue, et aucun signal excès est observé dans les données, observées (attendues) des limites supérieures (pour MH=125 GeV) sont fixés au niveau de confiance de 95% sur le rapport de la section du patrimoine mondial de croix multiplié par le rapport de branchement de H→b¯b pour sa prédiction du modèle standard, qui représentent 4,8 (4,7) fois l'attente du Modèle Standard. Cette procédure est effectuée en utilisant une approche semi- fréquentiste pour prendre efficacement en compte les incertitudes systématiques, qui se trouvent à dégrader la sensibilité d'environ 20 % une fois pris en compte et après en minimisant leur impact en les contraignant à des données. Le résultat présenté dans cette thèse, basée sur une luminosité intégrée de 9. 7 fb-1 a été publié à l'origine dans la physique avis Lettre en Septembre 2012, et avec quelques petites modifications en physique critique D en Septembre 2013. Il est inclus dans le D0 et dans la combinaison Tévatron. Les résultats des H→b¯b recherches ont été validées par une mesure de la diboson (WZ+ZZ) de section transversale de la production
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Jakobi, Katharina [Verfasser]. « Search for Physics Beyond the Standard Model with a Shape Fit Method in Final States with Jets and Missing Transverse Energy at the ATLAS Experiment / Katharina Jakobi ». Mainz : Universitätsbibliothek Mainz, 2020. http://d-nb.info/1204019037/34.
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Perego, Marta Maria. « Search for new physics produced via Vector Boson Fusion in final states with large missing transverse momentum with the ATLAS detector ». Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS088/document.
Texte intégralRésumé :
Cette thèse présente des recherches sur la nouvelle physique produite par le processus de Fusion de Bosons Vecteur (VBF) dans les états finaux avec une grand impulsion transverse manquante (Etmiss) en utilisant 36.1 fb⁻¹ de données de collisions proton-proton avec une énergie dans le centre de masse de 13 TeV, recueillies par l'expérience ATLAS au Large Hadron Collider (LHC) au CERN en 2015 et 2016. En particulier, elle se concentre sur la recherche de la désintégration invisible du boson de Higgs produit via le mode VBF. Comme le modèle standard de la physique des particules (MS) prédit une désintégration invisible de Higgs uniquement à travers le mode H->ZZ*->4v avec un rapport d’embranchement BR ~ 0,1%, si une désintégration en particules invisibles du boson de Higgs était observée avec un BR supérieur, ce serait un signe de nouvelle physique. Plusieurs modèles au-delà du modèle standard (BSM) prédisent des désintégrations du boson de Higgs en particules de matière noire (DM, non détectées) ou en particules massives neutres à vie longue. Parmi les recherches H->particules invisibles, la plus sensible est celle où le Higgs est produit via le mode VBF. Son état final est caractérisé par deux jets énergétiques, avec les caractéristiques typiques du mode VBF (c'est-à-dire une grande séparation angulaire et une grande masse invariante des deux jets) et une grande impulsion transverse manquante (Etmiss>180 GeV). Pour sélectionner un échantillon d'événements candidats de signal, une région de signal (SR) est définie pour maximiser la fraction d'événements de signal attendus par rapport à la prédiction du MS (bruit de fond). Les processus MS qui peuvent peupler la SR proviennent principalement des processus Z->vv+jets et W->lv+jets, où le lepton est perdu ou non reconstruit. Leur contribution est estimée avec une approche semi-data driven : des régions dédiées enrichies en événements W->lv/Z->ll sont utilisées pour normaliser les données des estimations de Monte Carlo (MC) en utilisant une technique de fit simultané (méthode du facteur de transfert) et pour les extrapoler à la SR. L'estimation de fond prédit est comparée aux données SR observées. Comme aucun excès n'est trouvé, une limite supérieure sur le BR (H-> invisible) est calculée. L'analyse est ensuite réinterprétée dans le cadre de modèles inspirés du modèle Minimal Dark Matter. Le cas d'un nouveau triplet fermionique électrofaible, avec une hypercharge nulle et avec interactions respectant le nombre B-L, ajouté au MS fournit un bon candidat Dark Matter (WIMP pure). Si on considère l'abondance thermique, la masse du composant neutre est d’environ 3 TeV. Cependant des masses plus faibles sont également envisageables dans le cas de mécanismes de production non thermiques ou lorsque le triplet ne constitue qu'une fraction de l'abondance de DM. Il peut être produit à des collisionneurs proton-proton tels que le LHC et il peut être sondé de différentes manières. Une fois produites, les composantes chargées du triplet se désintègrent dans le composant neutre le plus léger, χ0 , avec en plus des pions très mous, en raison de la petite différence de masse entre les composants neutres et chargés. Ces pions de très faible impulsion ne peuvent pas être reconstruits et sont donc perdus. Le χ0 est reconstruit comme de l’Etmiss dans le détecteur. Par conséquent, lorsqu'il est produit via VBF, il donne lieu à une signature avec deux jets VBF et de l’Etmiss, le même état final que celui qui a été étudié pour l'analyse de VBF H->invisible. Des points de masse différentes (de 90 GeV à 200 GeV) ont été engendrés avec les programmes Monte Carlo Madgraph+Pythia, dans le cadre du logiciel officiel ATLAS, et les limites supérieures sont définies sur la section efficace fiducielle de production. Des extrapolations à des luminosités plus élevées (Run3 et HL-LHC) en utilisant une approche simplifiée sont également présentéesThis thesis presents searches for new physics produced via Vector Boson Fusion (VBF) in final states with large Missing Transverse Momentum (Etmiss) using 36.1 fb⁻¹ of data from proton-proton collisions at center-of-mass-energy of 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider at CERN during 2015 and 2016. In particular, it focuses on the search for the invisible decay of the Higgs boson produced via the vector boson fusion (VBF) process. As the SM predicts an Higgs invisible decay only through H->ZZ*->4v with Branching Ratio BR~0.1%, if an invisibly decaying Higgs boson would be observed with a higher BR, this would be a sign of new physics. Several Beyond the Standard Model (BSM) models predict invisibly decaying Higgs boson where the Higgs can decay into dark matter particles or neutral long-lived massive particles. Among the H->invisible searches the most sensitive one is the one where the Higgs is produced via the VBF process. Its final state is characterized by two energetic jets, with the typical features of the VBF mode (i.e. large angular separation and large invariant mass) and large missing transverse momentum (Etmiss>180 GeV). To select a sample of signal candidate events, a Signal Region (SR) is designed to maximize the fraction of expected signal events with respect to the SM prediction (backgrounds). The SM processes which can populate the SR comes mainly from Z->vv+jets and W->lv+jets processes, where the lepton is lost or not reconstructed. Their contribution is estimated with a semi data driven approach: dedicated regions enriched in W->lv/Z->ll events are used to normalize to data the Monte Carlo (MC) estimates using a simultaneous fitting technique (transfer factor) and to extrapolate them to the SR. The predicted background estimate is compared to the observed SR data. Since no excess is found, an upper limit on the BR(H->inv) is set. The analysis is then reinterpreted in the context of models inspired by the Minimal Dark Matter model. The case of a new electroweak fermionic triplet, with null hypercharge and with interactions respecting the B-L number, added on top of the SM provides a good Dark Matter candidate. As such, it is an example of pure Weakly Interacting Massive Particle (WIMP), meaning that it is a DM particle with SU(2)_L SM interactions which is not mixing with other states (pure).If the thermal abundance is assumed, the mass of the neutral component is around 3 TeV, however smaller masses are also allowed in case of non-thermal production mechanisms or if the triplet constitutes only a fraction of the DM abundance. It can be produced at proton-proton colliders such as the LHC and it can be probed in different ways. Once produced, the charged components of the triplet decays into the lightest neutral component chi0 plus very soft charged pions. chi0 is reconstructed as Etmiss in the detector while the pions, because of the small mass splitting between the neutral and charged components, are so soft that are lost and are not reconstructed. Therefore, when produced via VBF, it gives rise to a signature with two VBF jets and Etmiss, the same final state that has been investigated for the VBF Higgs invisible analysis. Different mass point (from 90 GeV to 200 GeV) have been generated with the Madgraph+Pythia, Monte Carlo programs within the official ATLAS software, and upper limits are set on the fiducial cross section. Extrapolations to higher luminosities using a simplified approach are also presented
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Agaras, Merve Nazlim. « Searches for associated Higgs Boson production with top quark pair and Higgs pair production in multi lepton final states with the ATLAS detector ». Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC023.
Texte intégralRésumé :
Depuis la découverte du boson de Higgs à une masse d'environ 125 GeV par les deux collaborations ATLAS et CMS en juillet 2012, il est devenu crucial de mesurer ses propriétés, telles que ses couplages avec d'autres particules, et de rechercher tout écart par rapport aux prévisions du Modèle Standard (SM). Le couplage Yukawa du quark top est proche de l'unité et est le plus fort dans le secteur fermionique. Par conséquent, ce couplage joue un rôle crucial dans la théorie. La détermination de la production de boson de Higgs avec une paire de quarks top (ttH) offre un accès a l'ordre dominant pour mesurer ce couplage. L'analyse de la production de ttH dans le cadre de l'expérience ATLAS exploite plusieurs canaux de désintégration du Higgs, ainsi que différents modes de désintégration des quarks top. Dans cette thèse, l'étude du processus ttH (H → Multi lepton) est présentée dans la topologie où le Higgs se désintègre en WW,ZZ ou tautau, en utilisant un ensemble de données correspondant à une luminosité intégrée de 79,8fb^-1 à √s = 13 TeV, recueillies avec le détecteur ATLAS entre 2015 et 2017. L'amélioration des connaissances sur la modélisation des bruits de fond et un modèle d'ajustement complexe est utilisée avec de nombreux degrés de liberté. Des ajustements particulièrement différents sont présentés afin de comprendre la modélisation du principal bruit de fond irréductible, ttW. En outre, une recherche sur la production de paires de bosons de Higgs dans les états finaux multi leptoniques est présentée. La recherche utilise 139fb^-1 de données issues de collisions proton-proton à une énergie de centre de masse de 13 TeV fournies par le Grand collisionneur de hadrons (LHC) et enregistrées par l'expérience ATLAS entre 2015 et 2018. Les premières études du canal 2 leptons de même signe sont réalisées afin d'optimiser le point de fonctionnement des leptons et d'estimer les contributions des bruits de fond. La méthode d'ajustement du modèle est appliquée pour estimer les bruits de fond réductibles et calculer la limite supérieure préliminaire prévueSince the discovery of the Higgs boson at a mass around 125 GeV by both ATLAS and CMS collaborations in July 2012, it became crucial to measure its properties, such as its couplings to other particles, and search for any deviations from the Standard Model (SM) predictions. The top quark Yukawa coupling is close to unity and the strongest in the fermionic sector. Therefore, this coupling plays a crucial role in the theory. Determination of the associated production of The Higgs boson production with a pair of top quarks (ttH) offers a tree-level access to measuring this coupling. The analysis of ttH production at ATLAS experiment exploits several Higgs decay channel, together with different top quark decay modes. In this thesis, the study of the ttH (H → Multi lepton) process is presented in the topology where the Higgs decays to WW,ZZ or tautau, using a dataset corresponding to an integrated luminosity of 79.8fb^-1 at √s = 13 TeV, collected with the ATLAS detector between 2015-2017. Improved knowledge on the background modelling and the complex fit model is used with many degrees of freedoms. Particularly different fit setups are presented in order to understand the modelling of the major irreducible background, ttW. Furthermore, a search for the SM Higgs boson pair production in the multi lepton final states is presented. The search uses 139fb^-1 of proton-proton collisions data at a centre-of-mass energy of 13 TeV provided by the Large Hadron Collider (LHC) and recorded by the ATLAS experiment in 2015 and 2018. The first studies in two lepton same-sign channel is performed for lepton working point optimisation and estimation of background contributions. Template fit method is applied to estimated the reducible backgrounds and preliminary expected upper limit is calculated
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Tonelli, Diego. « First observation of the Bs^0 → K+ K− decay mode, and measurement of the B^0 and Bs^0 mesons decay-rates into two-body, charmless final states at CDF ». Doctoral thesis, Scuola Normale Superiore, 2006. http://hdl.handle.net/11384/85835.
Texte intégral
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Mamužić, Judita. « Search for Gaugino Mediation Non-Universal Higgs Masses Model with Tau-Sneutrino NLSP withthe ATLAS Detector in Final States with Jets and Missing Transverse Momentum and 20.3 fb-1of sqrt(s) = 8 TeV Proton-Proton Collision Data ». Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17618.
Texte intégralRésumé :
Supersymmetrie (SUSY) ist eine der am besten motivierten Erweiterungen des Standardmodells, und Suchen nach Hinweisen auf Supersymmetrie am LHC sind ein wichtiger Beitrag zum Verständnis von neuer Physik. Das Thema dieser Doktorarbeit ist die Analyse von zwei SUSY-Szenarien unter Verwendung von 20.3 fb−1 an ATLAS Daten, die bei einer Schwerpunktenergie von 8 TeV aufgezeichnet wurden. Den Hauptteil der Arbeit stellt eine Untersuchung des "Nicht-Universelle Higgs Massen Modells mit Gaugino Mediation" (NUHMG) mit Tau-Sneutrino als NLSP dar. Es wurde gezeigt, dass NUHMG unter Verwendung von Ereignissen ohne Leptonen, mit mehreren Jets, und fehlendem Transversalimpuls zu finden sein müsste. Eine neue Methode zur schnellen Optimierung unter Verwendung von multivariaten Methoden wurde entwickelt und in die Analyse eingebracht. Da kein signikanter Überschuss an Ereignissen in den untersuchten Daten beobachtet wurde, wurden experimentell ausgeschlossene Parameterbereiche des NUHMG-Modells bestimmt (bei einem Konfidenzniveau von 95 Prozent). Hierbei wurden Squark und Gluino Massen unterhalb von 1250 GeV bzw. 1400 GeV ausgeschlossen. Das zweite SUSY-Modell, das in dieser Doktorarbeit untersucht wird, ist das Nicht-Universelle Higgs Massen Modell (NUHM) mit Neutralino als LSP, welches innerhalb der Theorie der “Radiatively Driven Natural SUSY” (RNS) motiviert ist. Eine Datenanalyse mit einer statistischen Kombination von Ereignissen mit 2 bis 4 Leptonen wurde durchgeführt. Da kein signikanter Überschuss von Ereignissen beobachtet wurde, wurden ausgeschlossene Parameterbereiche des RNS-NUHM Modells bestimmt. Der größte Beitrag kommt hierbei von der Analyse mit 3 Leptonen, und es werden Werte von m1/2Supersymmetry (SUSY) is one of the best motivated extensions of the Standard Model. The subject of this thesis is the analysis of two SUSY scenarios using 20.3 fb-1 of ATLAS data at 8 TeV center of mass energy. The main topic is a study of the Non-Universal Higgs Masses model with Gaugino mediation and Tau-Sneutrino NLSP (NUHMG). A study showed that NUHMG can be found using Squark and Gluino production, using final states with zero leptons of transverse momenta higher than 10 GeV, multiple jets and missing transverse energy. A new method for fast optimisation using multivariate techniques was developed for the analysis with 2-6 jets and missing transverse momentum. No significant excess of data has been seen, and 95 percent CL exclusion limits have been set on the model, where Squark and Gluino masses are excluded up to 1250 and 1400 GeV respectively. Second SUSY model studied, is the Non-universal Higgs Masses model with Neutralino LSP (NUHM). It is well motivated in the framework of Radiatively Driven Natural Supersymmetry (RNS). A data analysis using a statistical combination of 2, 3 and 4 leptons has been performed. No significant excess of data has been observed, and 95 percent CL exclusion limits have been set. They reach up to 300 GeV in m1/2, and extend up to the highest tested value of μ = 500 GeV. In addition to physics analyses, a program developed for online monitoring of the ATLAS trigger, called Trigger Presenter (TriP), is described in this thesis.
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Horner, Stephan [Verfasser], et Gregor [Akademischer Betreuer] Herten. « Search for Supersymmetry in single-lepton final states with the ATLAS detector and Improved background model for the search of new physics = Suche nach Supersymmetry in Einzel-Lepton-Endzuständen mit dem ATLAS-Detektor und Verbessertes Untergrundmodell für die Suche nach Neuer Physik ». Freiburg : Universität, 2011. http://d-nb.info/1123459878/34.
Texte intégral
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Mamužić, Judita [Verfasser], Klaus [Gutachter] Mönig, Thomas [Gutachter] Lohse et Sascha [Gutachter] Caron. « Search for Gaugino Mediation Non-Universal Higgs Masses Model with Tau-Sneutrino NLSP with the ATLAS Detector in Final States with Jets and Missing Transverse Momentum and 20.3 fb-1 of sqrt(s) = 8 TeV Proton-Proton Collision Data / Judita Mamužić ; Gutachter : Klaus Mönig, Thomas Lohse, Sascha Caron ». Berlin : Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://d-nb.info/1117081273/34.
Texte intégral
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Anger, Philipp. « Probing Electroweak Gauge Boson Scattering with the ATLAS Detector at the Large Hadron Collider ». Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-151612.
Texte intégralRésumé :
Electroweak gauge bosons as central components of the Standard Model of particle physics are well understood theoretically and have been studied with high precision at past and present collider experiments. The electroweak theory predicts the existence of a scattering process of these particles consisting of contributions from triple and quartic bosonic couplings as well as Higgs boson mediated interactions. These contributions are not separable in a gauge invariant way and are only unitarized in the case of a Higgs boson as it is described by the Standard Model. The process is tied to the electroweak symmetry breaking which introduces the longitudinal modes for the massive electroweak gauge bosons. A study of this interaction is also a direct verification of the local gauge symmetry as one of the fundamental axioms of the Standard Model. With the start of the Large Hadron Collider and after collecting proton-proton collision data with an integrated luminosity of 20.3/fb at a center-of-mass energy of 8 TeV with the ATLAS detector, first-ever evidence for this process could be achieved in the context of this work.
A study of leptonically decaying WWjj, same-electric-charge diboson production in association with two jets resulted in an observation of the electroweak WWjj production with same electric charge of the W bosons, inseparably comprising WW->WW electroweak gauge boson scattering contributions, with a significance of 3.6 standard deviations. The measured production cross section is in agreement with the Standard Model prediction.
In the course of a study for leptonically decaying WZ productions, methods for background estimation, the extraction of systematic uncertainties and cross section measurements were developed. They were extended and applied to the WZjj final state whereof the purely electroweakly mediated contribution is intrinsically tied to the scattering of all Standard Model electroweak gauge bosons: Wγ->WZ and WZ->WZ. Three charged leptons and a neutrino from the decay of the final state bosons allow inferences about the scattering process. A distinct signature is provided by the two accompanying tagging jets as remnants of the incoming quarks radiating the initial electroweak gauge bosons. The cross section of the electroweak WZjj production was measured to σ(fiducial, observed) = (0.63 +0.32 -0.28 (stat.) +0.41 -0.24 (syst.)) fb and was found to be consistent with the Standard Model prediction at next-to-leading order in perturbative quantum chromodynamics, σ(fiducial, theory) = (0.31 +0.03 -0.05) fb. Unfolded differential cross sections of kinematic variables sensitive to models of new physics were derived. Anomalous quartic electroweak gauge couplings are introduced as dimensionless coupling parameters of additional operators within an effective field theory approach. Constraints on the parameters of operators with dimension eight were set employing a unitarization prescription based on form factors.
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Fenollosa, Artés Felip. « Contribució a l'estudi de la impressió 3D per a la fabricació de models per facilitar l'assaig d'operacions quirúrgiques de tumors ». Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667421.
Texte intégralRésumé :
La present tesi doctoral s’ha centrat en el repte d’aconseguir, mitjançant Fabricació Additiva (FA), models per a assaig quirúrgic, sota la premissa que els equips per fer-los haurien de ser accessibles a l’àmbit hospitalari. L’objectiu és facilitar l’extensió de l’ús dels prototips com a eina de preparació d’operacions quirúrgiques, transformant la pràctica mèdica actual de la mateixa manera que en el seu moment ho van fer tecnologies com les que van facilitar l’ús de radiografies. El motiu d’utilitzar FA, en lloc de tecnologies més tradicionals, és la seva capacitat de materialitzar de forma directa les dades digitals obtingudes de l’anatomia del pacient mitjançant sistemes d’escanejat tridimensional, fent possible l’obtenció de models personalitzats. Els resultats es centren en la generació de nou coneixement sobre com aconseguir equipaments d’impressió 3D multimaterials accessibles que permetin l’obtenció de models mimètics respecte als teixits vius. Per facilitar aquesta buscada extensió de la tecnologia, s’ha focalitzat en les tecnologies de codi obert com la Fabricació per Filament Fos (FFF) i similars basades en líquids catalitzables. La recerca s’alinea dins l’activitat de desenvolupament de la FA al CIM UPC, i en aquest àmbit concret amb la col·laboració amb l’Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloc de la tesi inclou la descripció de l’estat de l’art, detallant les tecnologies existents i la seva aplicació a l’entorn mèdic. S’han establert per primer cop unes bases de caracterització dels teixits vius -sobretot tous- per donar suport a la selecció de materials que els puguin mimetitzar en un procés de FA, a efectes de millorar l’experiència d’assaig dels cirurgians. El caràcter rígid dels materials majoritàriament usats en impressió 3D els fa poc útils per simular tumors i altres referències anatòmiques. De forma successiva, es tracten paràmetres com la densitat, la viscoelasticitat, la caracterització dels materials tous a la indústria, l’estudi del mòdul elàstic de teixits tous i vasos, la duresa d’aquests, i requeriments com l’esterilització dels models. El segon bloc comença explorant la impressió 3D mitjançant FFF. Es classifiquen les variants del procés des del punt de vista de la multimaterialitat, essencial per fer models d’assaig quirúrgic, diferenciant entre solucions multibroquet i de barreja al capçal. S’ha inclòs l’estudi de materials (filaments i líquids) que serien més útils per mimetitzar teixits tous. Es constata com en els líquids, en comparació amb els filaments, la complexitat del treball en processos de FA és més elevada, i es determinen formes d’imprimir materials molt tous. Per acabar, s’exposen sis casos reals de col·laboració amb l’HJSD, una selecció d’aquells en els que el doctorand ha intervingut en els darrers anys. L’origen es troba en la dificultat de l’abordatge d’operacions de resecció de tumors infantils com el neuroblastoma, i a la iniciativa del Dr. Lucas Krauel. Finalment, el Bloc 3 té per objecte explorar nombrosos conceptes (fins a 8), activitat completada al llarg dels darrers cinc anys amb el suport dels mitjans del CIM UPC i de l’activitat associada a treballs finals d’estudis d’estudiants de la UPC, arribant-se a materialitzar equipaments experimentals per validar-los. La recerca ampla i sistemàtica al respecte fa que s’estigui més a prop de disposar d’una solució d’impressió 3D multimaterial de sobretaula. Es determina que la millor via de progrés és la de disposar d’una pluralitat de capçals independents a fi de capacitar la impressora 3D per integrar diversos conceptes estudiats, materialitzant-se una possible solució. Cloent la tesi, es planteja com seria un equipament d’impressió 3D per a models d’assaig quirúrgic, a fi de servir de base per a futurs desenvolupaments.La presente tesis doctoral se ha centrado en el reto de conseguir, mediante Fabricación Aditiva (FA), modelos para ensayo quirúrgico, bajo la premisa que los equipos para obtenerlos tendrían que ser accesibles al ámbito hospitalario. El objetivo es facilitar la extensión del uso de modelos como herramienta de preparación de operaciones quirúrgicas, transformando la práctica médica actual de la misma manera que, en su momento, lo hicieron tecnologías como las que facilitaron el uso de radiografías. El motivo de utilizar FA, en lugar de tecnologías más tradicionales, es su capacidad de materializar de forma directa los datos digitales obtenidos de la anatomía del paciente mediante sistemas de escaneado tridimensional, haciendo posible la obtención de modelos personalizados. Los resultados se centran en la generación de nuevo conocimiento para conseguir equipamientos de impresión 3D multimateriales accesibles que permitan la obtención de modelos miméticos respecto a los tejidos vivos. Para facilitar la buscada extensión de la tecnología, se ha focalizado en las tecnologías de código abierto como la Fabricación por Hilo Fundido (FFF) y similares basadas en líquidos catalizables. Esta investigación se alinea dentro de la actividad de desarrollo de la FA en el CIM UPC, y en este ámbito concreto con la colaboración con el Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloque de la tesis incluye la descripción del estado del arte, detallando las tecnologías existentes y su aplicación al entorno médico. Se han establecido por primera vez unas bases de caracterización de los tejidos vivos – principalmente blandos – para dar apoyo a la selección de materiales que los puedan mimetizar en un proceso de FA, a efectos de mejorar la experiencia de ensayo de los cirujanos. El carácter rígido de los materiales mayoritariamente usados en impresión 3D los hace poco útiles para simular tumores y otras referencias anatómicas. De forma sucesiva, se tratan parámetros como la densidad, la viscoelasticidad, la caracterización de materiales blandos en la industria, el estudio del módulo elástico de tejidos blandos y vasos, la dureza de los mismos, y requerimientos como la esterilización de los modelos. El segundo bloque empieza explorando la impresión 3D mediante FFF. Se clasifican las variantes del proceso desde el punto de vista de la multimaterialidad, esencial para hacer modelos de ensayo quirúrgico, diferenciando entre soluciones multiboquilla y de mezcla en el cabezal. Se ha incluido el estudio de materiales (filamentos y líquidos) que serían más útiles para mimetizar tejidos blandos. Se constata como en los líquidos, en comparación con los filamentos, la complejidad del trabajo en procesos de FA es más elevada, y se determinan formas de imprimir materiales muy blandos. Para acabar, se exponen seis casos reales de colaboración con el HJSD, una selección de aquellos en los que el doctorando ha intervenido en los últimos años. El origen se encuentra en la dificultad del abordaje de operaciones de resección de tumores infantiles como el neuroblastoma, y en la iniciativa del Dr. Lucas Krauel. Finalmente, el Bloque 3 desarrolla numerosos conceptos (hasta 8), actividad completada a lo largo de los últimos cinco años con el apoyo de los medios del CIM UPC y de la actividad asociada a trabajos finales de estudios de estudiantes de la UPC, llegándose a materializar equipamientos experimentales para validarlos. La investigación amplia y sistemática al respecto hace que se esté más cerca de disponer de una solución de impresión 3D multimaterial de sobremesa. Se determina que la mejor vía de progreso es la de disponer de una pluralidad de cabezales independientes, a fin de capacitar la impresora 3D para integrar diversos conceptos estudiados, materializándose una posible solución. Para cerrar la tesis, se plantea cómo sería un equipamiento de impresión 3D para modelos de ensayo quirúrgico, a fin de servir de base para futuros desarrollos.
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Bristow, Kieran Matthew. « A search for a standard model higgs boson decaying to two T leptons in the lepton-hadron final state ». Thesis, 2014. http://hdl.handle.net/10539/15604.
Texte intégralRésumé :
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2014.This thesis presents multiple studies contributing to the research conducted at the ATLAS experiment at the CERN facility in Switzerland. The areas of contribution include the ATLAS physics validation developments and the Standard Model Higgs boson decaying to two tau leptons search e ort. A section outlining the use and maintenance of the ATLAS TauValidation package details contributions made towards the ATLAS physics validation program.
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AMBRA, TERENCE. « Approaches for the service composition and description towards the Web-Telecom convergence ». Doctoral thesis, 2015. http://hdl.handle.net/2158/992206.
Texte intégralRésumé :
In this PhD thesis I discuss how I applied a REST-oriented methodology to design a set of REST APIs for communication services (e.g. a voice call and presence service). The contribution of this work is threefold. Firstly, I formalize the call resource behavior through a Finite State Machine representation which accounts for the SIP specifications and for REST constraints. Secondly, I simulate the service expected behavior and its interworking with SIP User Agents through a tool for the
analysis of communicating state machines. Thirdly, I present the
implementation details of a web application prototype and evaluate its functional correctness and performance. This prototype supports three mechanisms for handling asynchronous notications (i.e., WebSocket, Long Polling and HTTP Streaming).
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Hamity, Guillermo Nicolas. « Search for an A boson decaying to Zh, within the fully hadronic ℓℓィィ final state, in pp collision data recorded at √s = 8 TeV with the ATLAS experiment ». Thesis, 2015. http://hdl.handle.net/10539/18517.
Texte intégralRésumé :
Thesis presented in fulfilment of the requirements for the degree of Master of Science in Physics at the University of the Witwatersrand School of Physics, University of the Witwatersrand, 2015.A search for the pseudoscalar A boson, which is predicted by in many models with an extended Higgs sector, gives a gateway to searches for physics beyond the Standard Model (SM). This thesis presents the results of a search for gluon-fusion produced A in the decay to Zh, with a final state of two electrons or muons and two τ leptons, in 20.3 fb−1of proton-proton collision data at √s = 8 TeV. Each tau lepton is allowed to dacay either leptonically, τlep, or hadronically,τhad, giving rise to three final states, τlepτlep, τlepτhad and τhadτhad. Focus is placed on the methodology and results of the fully hadronic channel. No evidence for the existence of an A boson is found in the scanned range of 220 ≤ mA ≤ 1000 GeV and 95% CL upper limits are placed on the gluon-fusion cross section times branching ratio, σ × BR(A → Zh) × BR(h → ℓℓττ). The results are combined with a complementing A → Zh search, where h → b¯b, and interpreted in view of two-Higgs-Doublet-Models (2HDMs), where exclusion limits are placed on large sections of phasepace.
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Finelli, Kevin. « An Inclusive Analysis of Top Quark Pair, W Boson Pair, and Drell-Yan Tau Lepton Pair Production in the Dilepton Final State from Proton-Proton Collisions at Center-of-Mass Energy 7 TeV with the ATLAS Detector ». Diss., 2013. http://hdl.handle.net/10161/8194.
Texte intégralRésumé :
A simultaneous measurement of three Standard Model cross-sections using 4.7 inverse femtobarns of proton-proton collision data at a center-of-mass energy of 7 TeV is presented. Collision data were collected using the ATLAS detector at the Large Hadron Collider. The signal production cross-sections studied are for top quark pair production, charged weak boson pair production, and Drell-Yan production of tau lepton pairs with invariant mass greater than 40 GeV. A data sample is defined from events with isolated high-energy electron-muon pairs arranged in a phase space defined by missing transverse momentum and jet multiplicity. A binned maximum likelihood fit is employed to determine signal yields in this phase space. Signal event yields are in turn used to measure full cross-section values and cross-section values within a fiducial region of the detector, and unlike conventional measurements the signal measurements are performed simultaneously. This is the first such simultaneous measurement of these cross-sections using the ATLAS detector. Measured cross-sections are found in good agreement with the most precise published theoretical predictions.
Dissertation
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Wang, Ann Miao. « New Physics Models in the Diphoton Final State at CMS ». Thesis, 2015. https://thesis.library.caltech.edu/9535/1/wang_ann_2015_thesis.pdf.
Texte intégralRésumé :
Since the discovery of the Higgs boson at the LHC, its use as a probe to search for beyond the standard model physics, such as supersymmetry, has become important, as seen in a recent search by the CMS experiment using razor variables in the diphoton final state. Motivated by this search, this thesis examines the LHC discovery potential of a SUSY scenario involving bottom squark pair production with a Higgs boson in the final state. We design and implement a software-based trigger using the razor variables for the CMS experiment to record events with a bottom quark-antiquark pair from a Higgs boson. We characterize the full range of signatures at the LHC from this Higgs-aware SUSY scenario and demonstrate the sensitivity of the CMS data to this model.
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Klein, Matthew Henry. « Search for R-parity violating supersymmetry in multilepton final states using the ATLAS detector ». Thesis, 2017. https://doi.org/10.7916/D83T9HTM.
Texte intégralRésumé :
This thesis presents a search for R-parity violating supersymmetry at sqrt(s)=13 TeV, using approximately 13.3 fb-1 of data collected by ATLAS in 2015 and the first half of 2016. Events are required to contain at least four leptons (electrons or muons only) that are not the product of a Z boson decay, and this requirement results in a low Standard Model background and a high sensitivity to various physics models beyond the Standard Model. No significant deviations from the Standard Model are observed in data, and results are used to set upper limits on the event yields from processes beyond the Standard Model. In a simplified model of chargino production with indirect R-parity violating decays, limits are extended by approximately 400 GeV relative to the Run 1 search, excluding chargino masses below 1.1 TeV.
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Tian, Feng. « Search for the Standard Model Higgs boson in Z + γ ; final states with the ATLAS detector at the LHC ». Thesis, 2014. https://doi.org/10.7916/D8G73BP1.
Texte intégralRésumé :
This dissertation describes a search for the Standard Model Higgs boson in Z+photon channel with the ATLAS detector at the LHC using 4.6 fb⁻¹ of proton-proton collisions at center of mass energy 7 TeV in 2011 and 20.7 fb⁻¹ of proton-proton collisions at center of mass energy 8 TeV in 2012. The distribution of the mass difference between M_Zphoton and M_Z is compared to the Standard Model (SM) background expectations. No significant deviation from the SM prediction is observed and the upper limits on the signal strength μ of a Higgs boson with a mass between 120 and 150 GeV are derived. The expected exclusion limits at 95% confidence level range between 7.3 and 22.3 times the predicted Standard Model cross section. The observed exclusion limits range between 5.3 and 38.7 times the Standard Model cross section. For a Higgs boson with mass of 125.5 GeV, the expected and observed limits are 13.2 and 17.0 times the Standard Model respectively.
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Mann, Alexander. « Calorimeter-Based Triggers at the ATLAS Detector for Searches for Supersymmetry in Zero-Lepton Final States ». Doctoral thesis, 2012. http://hdl.handle.net/11858/00-1735-0000-0006-B54D-0.
Texte intégral
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« Search for Standard Model Higgs bosons produced in association with top-quark pairs in ttH multilepton final states using the ATLAS detector at the LHC ». Berlin : Humboldt-Universität zu Berlin, 2021. http://d-nb.info/1230406778/34.
Texte intégral
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Gaspar, Carlos Pedro Marques. « Comparação dos processos orçamentais : o caso de Portugal nos países da OCDE ». Master's thesis, 2015. http://hdl.handle.net/10071/10799.
Texte intégralRésumé :
Esta dissertação procura refletir sobre o processo orçamental nas suas fases mais determi-nantes. Inicialmente procede-se a uma apresentação de conceitos que é posteriormente com-pletada com a exposição das experiências reais num número relevante de países. Esta análi-se teórica, completada com práticas orçamentais, permitirá formar uma ideia mais sólida sobre a realidade. A comparação de diferentes realidades normativas, socioculturais, económicas, financeiras e políticas solidifica esta análise.
A investigação tem como objetivo aprender com diferentes práticas procurando arrolar o que está em maior dissonância com a realidade portuguesa. Estas diferenças encontradas podem vir a ser objeto de projetos de melhoria na procura de um sistema orçamental mais resiliente.
O presente trabalho estrutura-se em três capítulos. No primeiro capítulo apresenta-se o caráter específico e o enquadramento legal da Administração Pública, assim como os mais importantes modelos teóricos de organização das administrações públicas e as origens do Orçamento do Estado usando, para tal, uma explanação bibliográfica. O segundo capítulo descreve e apresenta os principais conceitos sobre os temas e as diversas fases do orçamen-to do Estado. Por fim, o terceiro capítulo apresenta os dados sobre os processos orçamentais dos países da OCDE, com referência a 2012, com base na “International Budget Practices and Procedures Database” que permite a comparação entre as práticas dos países, salientan-do especificamente o caso português.This dissertation seeks to reflect on the budgetary process and its most crucial stages. Firstly, there is a presentation of concepts that is further completed with the presentation of the current experiences in a relevant number of countries. This theoretical analysis, supplemented with budgetary practices will form a solid idea about the reality. The comparison of different regula-tory, socio-cultural, economic, financial and political realities solidifies the analysis. The investigation aims to learn from different practices looking for what is in greater disso-nance with the Portuguese reality. These differences may be a subject of improvement in search of a more resilient budgetary system. The present paper is structured in three chapters. The first chapter presents the specific characteristics and the legal framework of the public administration, as well as the most im-portant theoretical models of public management and the origins of the budget for the public sector. For this purpose it was used an explanation essay. The second chapter presents and describes the main concepts about the different stages of the budget of the public sector. Fi-nally, the third chapter presents data about the budgetary techniques in OECD countries, with reference to 2012, based on "International Budget Practices and Procedures Database" which allows the comparison between the practices of the countries, with a special emphasis on the Portuguese case.
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Zwierz, Marta. « Zakaz ne bis in idem w prawie administracyjnym ». Doctoral thesis, 2020. https://depotuw.ceon.pl/handle/item/3660.
Texte intégralRésumé :
Przedmiotem rozprawy doktorskiej jest zakaz ne bis in idem w prawie administracyj-nym. Autor zakłada, że zakaz ne bis in idem nie dotyczy już wyłącznie norm prawa karnego, ale ma charakter dyrektywy ogólnosystemowej, a więc posiadającej w pewnym sensie znacze-nie także z punktu widzenia norm prawa administracyjnego. Sama rozprawa doktorska składa się z pięciu rozdziałów poprzedzonych uwagami wstępnymi i zakończonych wnioskami. Autor stosuje formalno-dogmatyczną metodę badawczą.
W pierwszym rozdziale rozważa poszczególne aspekty obowiązywania zakazu ne bis in idem w prawie karnym. Autor udowadnia również, że za sprawą norm prawa międzynarodo-wego doszło do uwolnienia zakazu ne bis in idem spod reżimu prawa karnego.
W drugim rozdziale zwraca uwagę na specyficzną konstrukcję zakazu ne bis in idem jako zasady konstytucyjnej. W tym ujęciu autor stara się określić, czy posiada on charakter wiążący ustawodawcę i organy stosujące prawo. Istotne znaczenie z punktu widzenia autora ma także określenie, czy zakaz ne bis in idem wpisuje się do kręgu publicznych praw podmio-towych, czy w dalszym ciągu jest jedynie uzasadnionym oczekiwaniem obywateli. Autor zwraca uwagę na wyraźny podział materii prawnej w obszarze stosowania zakazu ne bis in idem na poziomie konstytucyjnym na dwie sfery: karania i sankcjonowania.
Punktem wyjścia dla rozważań prowadzonych w trzecim rozdziale jest uznanie, iż na zakres obowiązywania zakazu ne bis in idem w prawie administracyjnym wpływa orzecznic-two Trybunału Konstytucyjnego. Autor podejmuje się zatem ustalenia za sprawą jakich rodza-jów sankcji administracyjnych obywatele mogą domagać się ochrony prawnej.
W czwartym rozdziale zwraca uwagę na to, że w obszarze prawa materialnego walor ochronny zakazu ne bis in idem ogranicza się wyłącznie do niektórych z wielu możliwych wa-riantów zbiegu sankcji prawnych. Autor stoi na straży przekonania, zgodnie z którym zakres obowiązywania zakazu ne bis in idem znajduje swoje uzasadnienie w aksjologii prawa admini-stracyjnego. Wskazuje zatem na granicę wyznaczoną przez ustawodawcę pomiędzy typowymi środkami policji administracyjnej a środkami przymusu administracyjnego i sankcjami praw-nymi polegającymi na pozbawieniu lub ograniczeniu określonych kategorii uprawnień. Rozwa-ża zarazem jej zgodność w świetle klauzuli interesu publicznego oraz konstytucyjnego wymo-gu proporcjonalności reakcji prawnej na naruszenie obowiązku prawnego.
Piąty rozdział dotyczy proceduralnego aspektu zakazu ne bis in idem w prawie admini-stracyjnym. Autor zakłada, że w tym ujęciu jest on ściśle powiązany z przesłanką procesową res iudicata. Zmierza zatem do wykazania, że ma on znaczenie nie tylko na etapie postępowa-nia sądowoadministracyjnego, ale urzeczywistnia ideę niesioną za pomocą zakazu ne bis in idem już na drodze ogólnego postępowania administracyjnego. W tym rozdziale autor stara się dodatkowo udzielić odpowiedzi na pytanie, czy instytucja zagadnienia wstępnego i Rozstrzy-gnięcia tymczasowe mają istotne znaczenie z punktu widzenia zakazu ne bis in idem.The subject of the doctoral dissertation is the prohibition of ne bis in idem in adminis-trative law. The author assumes that the prohibition of ne bis in idem no longer concerns only criminal law standards, but that it is a system-wide directive which is, in some sense, also rele-vant from the point of view of the rules of administrative law. The doctoral disservice itself consists of five chapters preceded by preliminary observations and completed proposals. The author applies a formal-dogmatic test method. The first chapter examines the various aspects of the prohibition of ne bis in idem in criminal law. The author also proves that the prohibition of ne bis in idem from the criminal law regime has been liberated by the rules of international law. The second chapter draws attention to the specific design of the prohibition of ne bis in idem as a constitutional principle. In this regard, the author seeks to determine whether it is binding on the legislator and the authorities applying the law. It is also important for the au-thor to determine whether the prohibition of ne bis in idem forms part of the public subjective rights, or remains merely a legitimate expectation of citizens. The author draws attention to the clear breakdown of the legal matter in the area of application of the ne bis in idem prohibition at constitutional level into two spheres: punishment and sanctioning. The starting point for the considerations in the third chapter is that the case-law of the Constitutional Tribunal affects the scope of the ne bis in idem prohibition in administrative law. The author therefore undertakes to determine by which types of administrative sanctions citizens can claim legal protection. In the fourth chapter, it draws attention to the fact that, in the area of substantive law, the prohibition of ne bis in idem is limited to some of the many possible options of overlap-ping of legal sanctions. The author guards the conviction that the scope of the prohibition of ne bis in idem is justified in the axiology of administrative law. It therefore points to the bor-der set by the legislator between the typical measures of the administrative police and the means of administrative coerction and the legal sanctions of depriving or restricting certain categories of allowances. It also considers its compatibility in the light of the public interest clause and the constitutional requirement of proportionality of the legal response to breach of legal obligation. The fifth chapter concerns the procedural aspect of the prohibition of ne bis in idem in administrative law. The author assumes that in this regard it is closely linked to the procedural premise of res iudicata. It seeks, therefore, to demonstrate that it is relevant not only at the stage of the judicial procedure, but that it materialates the idea pursued by the prohibition of ne bis in idem by means of a general administrative procedure. In this chapter, the author seeks to further answer the question of whether the institution of preliminary issues and provi-sional decisions are of significant importance from the point of view of the prohibition of ne bis in idem.