Zugl.: Aachen, Techn. Hochsch., Habil.-Schrift, 2009

Universiẗat, Diss., 2000--Freiburg (Breisgau).

Techn. Hochsch., Diss., 2000--Aachen.

Techn. Hochsch., Diss., 2002--Aachen.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Este trabalho apresenta os resultados da primeira medida da secao de choque de producao W± e± utilizando dados de colisoes proton-proton com energia de centro de massa s = 13 TeV pelo detector ATLAS em dois regimes diferentes de operacao do Large Hadron Collider (LHC): um perodo de baixa luminosidade em que foram acumulados 81 pb1 de dados e que permitiram medir a secao de choque fiducial e total da producao de bosons W+ e W na regiao inclusiva (regiao de massa transversa acima de 50 GeV, abrangendo o pico de massa transversa do boson W) e um perodo de alta luminosidade em que foi obtido 76,6 fb1 de dados tornando acessvel a medida da secao de choque fiducial de producao de bosons W+ e W na regiao de alta massa transversa (regiao de massa transversa entre 130 GeV e 2,5 TeV). As secoes de choque medidas e as distribuicoes cinematicas referentes a energia transversa faltante (ETmiss ), massa transversa do boson W (mTW), pseudorapidez (), momento transverso (pTe) do eletron decorrente do decaimento do W e a diferenca entre o angulo azimutal () do eletron e da ETmiss sao consistentes com previsoes teoricas obtidas em NLO e normalizadas em NNLO, considerando-se as incertezas sistematicas, estatsticas e na luminosidade. / This work presents the results of the first W± e± production cross section measurements in the proton-proton collisions at the center of mass energy of s = 13 TeV obtained with the ATLAS detector in two different operation regimes: a low luminosity period when 81pb1 of data was accumulated allowing the measurement of the fiducial and total production cross section of W+ and W bosons in the inclusive region (region of transverse mass above 50 GeV, covering the transverse mass peak of the W boson) and a high luminosity period when 76,6 fb1 made accessible the high W boson transverse mass region (between 130 GeV and 2.5 TeV), allowing the measurement of the fiducial cross section of W+ and W boson production. The measured cross sections and the kinematic distributions for the missing transverse energy, (ETmiss), W boson transverse mass (mTW), the pseudorapidity (), the transverse momentum (pTe) of the electron originated from the W boson decay as well as the azimuthal angle difference () between the electron and the ETmiss are consistent with the theoretical predictions obtained at NLO and normalized to NNLO, considering the systematic, statistical and luminosity uncertainties.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

The thesis analyses the damages caused by wild game in hunting districts (HD) of forest district (FD) Bučovice. The thesis focuses on factors affecting the amount of game damages on forest stands. Incurred damages for the period 2004 -- 2012 are compared with natural conditions, numbers of wild game and costs of forest protection against damages caused by wild game in management-plan areas (MPA) Bučovice and Račice. Based on collected data, the prognosis of development of game damages in hunting districts of MPA's Bučovice and Račice were developed. The results show that the main factor influencing the amount of game damages in FD Bučovice is high population of wild game.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresenta-se neste trabalho um estudo de produção difrativa de pares tt, na topologia de dupla troca de pómeron (DPE) inclusiva, nas condições do CMS para alta luminosidade (2 x 1033 cm-2s-1). O canal de decaimento para o sistema tt é o Semi-Leptônico, comum quark × top decaindo em um jato de b, um múon e um neutrino e o outro em jatos, sendo um deles de b (tt → bbqqμνμ). O processo acima foi simulado com o gerador DPEMC v2.4 [12], juntamente com o código de simulação FAMOS [41], versão 1.4.0, do CMS. Dois modelos teóricos foram utilizados, aqueles de Cox & Forshaw [10], [11] e de Boonekamp, Peschanskie Royon [13], [14]. Como background dominante, temos a combinação de um evento de tt não difrativo com eventos de pile-up (em média7) na mesma colisão de feixe no LHC. Como utilizam-se Roman Pots) para selecionar os eventos difrativos, eventos não ocorre relacionados de pile-up gerando prótons próximos à linha do feixe juntamente com um evento de tt não difrativo, são indistinguíveis experimentalmente do caso difrativo. Para uma luminosidade integrada de 10 fb-1, obtém-se da ordem de centenas de eventos para este background, enquanto que de O(1)a O (100) eventos do sinal difrativo, dependendo do modelo teórico utilizado. / Inclusive DPE (double pomeron exchange) production of t pairs was studied for CMS high luminosity running (2 x 1033cm-2s-1 ), with one top decaying into a b-jet, a muon and a neutrino, and the other to jets, one of them a b-jet (bbqqμνμ). The process was simulated with the generator DPEMC v2.4 [12], together with the fast CMS simulation code FAMOS [41], version 1.4.0. Two theoretical models were used for this analysis, that of Cox & Forshaw [10], [11] and of Boonekamp, Peschanski and Royon [13], [14]. As dominant background, we have the overlap of a non-diffractive tt event with pile-up events (7 in average) in the same bunch crossing. Since we use Roman Pots to tag the diffractive event, uncorrelated diffractive pile-up events generating very forward diffractive protons can fake the non-diffractive event as a diffractive one. For an integrated luminosity of 10 fb-1 we obtain a number of events of O (100) for this background, while (1) to O (100) for the diffractive signal, depending on the theoretical model used.

Malgré le succès incontestable du Modèle Standard de la physique des particules, il est vraisemblable qu'il ne soit qu'une partie de la théorie complète de physique des particules -- comme c'est le cas des hypothèses de théories unifiées -- et ainsi de nombreux efforts ont été dédiés au développement de théorie de Nouvelle Physique. La Supersymmétrie est l'une des extensions les plus populaires puisque qu'elle permet non seulement de résoudre le problème de Naturalité mais présente aussi une candidat viable de matière sombre. Ce dernier point a été particulièrement mis en avant avec les récentes mesures expérimentales qui ont permis d'affiner significativement notre connaissance des propriétés de cette matière sombre. En particulier, la détermination de la densité relique de matière sombre dans l'univers est à présent réalisée avec une précision de l'ordre du pourcent. Dans le cadre du Modèle Standard Supersymmétrique Minimal (le MSSM), cette contrainte permet ainsi de tester la structure à une boucle de la théorie. Cependant c'est aussi un modèle présentant un très grand nombre de paramètres, comparé au Modèle Standard, et le calcul complet des observables à une boucle reste trop long pour être effectué sur l'ensemble de l'espace des paramètres. Dans cette thèse, je me suis ainsi intéressé à la possibilité de reproduire ces corrections à la boucle par un ensemble de couplages effectifs. L'approche effective présentant l'avantage de garder la simplicité d'un calcul effectué à l'arbre tout en conservant une trace des effets caractéristiques de boucles comme le non-découplage de certaines particules lourdes. Le LHC (Large Hadron Collider), dont les opérations ont démarrées juste après le début de ma thèse, soit à l'automne 2009, a fourni des données complémentaires aux observables de matière sombre. En effet le secteur du Higgs du MSSM est très peu flexible, ce qui a pour effet d'introduire ce que l'on appelle le problème du ``fine-tuning'', c'est à dire la nécessité d'avoir des valeurs très précises pour les paramètres. Afin d'y remédier, de nombreux modèles ont été créés au delà du MSSM, comme le NMSSM (en anglais Next-to-MSSM). Dans le but de suivre une approche plus générale, j'ai décidé au cours de cette thèse d'utiliser à nouveau l'approche effective, mais dans un but différent : alors que les couplages effectifs utilisés dans le cas de la matière sombre sont choisi pour reproduire le plus fidèlement possible les corrections à la boucle des particules du MSSM, les opérateurs effectifs que nous ajoutons au secteur du Higgs sont les effets à basse énergie (c'est à dire l'énergie de production du Higgs) d'une nouvelle physique à haute énergie. Bien que dédiées à deux buts différents, ces deux implémentations d'une même technique montrent bien ses différents atouts. Dans un des cas (celui du Higgs) les opérateurs effectifs permettent de paramétrer l'effet d'une physique ultraviolette inconnue, alors que dans l'autre cas cette physique ultraviolette se réduit au simple MSSM. / Despite the numerous successes of the Standard Model of particle physics, it is believed that the complete picture of particle physics could be larger, as a unified theory for instance, and thus many efforts have been devoted to the development of theories of new physics. Supersymmetry is one of the most popular extensions since in addition to a solution of the naturalness issue, it provides a viable dark matter candidate. This last sector being all the more important now that recent experimental measurements have significantly increased our knowledge about dark matter properties, in particular the experimental determination of the relic density has reached the accuracy of a few percent. When applied to the Minimal Supersymmetric Standard Model (the MSSM, which is the simplest supersymmetric extension of the Standard Model), this constraint will thus shed light on the one-loop structure of the model. The MSSM is however much more liberal with unconstrained parameters than the Standard Model is, and the full one-loop computation of the relic density tends to be too long to be carried out throughout this large parameter space. In this thesis I have thus explored the opportunity of accounting for those loop corrections through a set of effective couplings. This effective approach has the advantage of keeping the simplicity of a tree-level computation but encoding at the same time genuine loop features such as the non-decoupling of heavy particles. Complementary to those constraints are the observables related to the LHC, which started taking data shortly after the beginning of my PhD in fall 2009. The Higgs sector of the MSSM is tightly constrained and this results in a certain fine-tuning of the model, which led to the creation of many models beyond the MSSM (such as the Next-to-Minimal Supersymmetric Standard Model). Arguing for a more general approach, I have decided in this thesis to use again the effective approach but with a different aim : while the effective couplings in the case of dark matter are determined to account for the MSSM loop corrections, the effective operators we add to the Higgs sector of the MSSM are the remnants of the integration of a heavy extra spectrum. This effective approach, called the BMSSM (for Beyond the MSSM) is known to account for many different realisations of non-minimal supersymmetry, and we have used it as a framework to recast the results of the Higgs analyses carried out by ATLAS and CMS collaborations. This study has led to the caracterisation of the rich phenomenology of the Higgs sector in the BMSSM, with in particular the possibility for a signal quite different from Standard Model or MSSM expectations. Though based on distinct aims, the two implementations of the effective approach show the different advantages of an effective field theory. In the first case the effective operators are parametrising the effect of an unknown UV completion, whereas in the second we assume this UV completion to be the MSSM.