Carbon Molecular Sieve (CMS) membranes have a potential to achieve attractive gas separation properties. CMS membranes in dense film configuration have shown promising results. Hence, for industrial application it’s important to translate this high performance in hollow fiber configuration. The key shortcoming in CMS hollow fiber fabrication has been the collapse of porous support resulting in lower gas separation productivities. Therefore, the goal of this study was to prevent the collapse in CMS hollow fibers by a process called as V-Treatment. The V-Treatment process uses the sol-gel reaction mechanism between organic-alkoxy silane (i.e. Vinyltrimethoxy Silane – VTMS) and moisture. The sol-gel reaction proposed in this study is a first-of-a-kind approach in asymmetric CMS membranes to create porous morphologies, and it can be easily integrated into the current asymmetric CMS membrane fabrication process. The V-treatment technique enables restricting the microscale morphology collapse in asymmetric CMS membranes without having a chemical reaction with the polymer precursor material.

The thesis work concentrated on the developments of selection strategies for the observation of MSSM Higgs bosons in the context of the CMS experiment. The thesis shows, by an example with a MSSM (Minimal Supersymmetric Standard Model) Higgs decaying into two tau, how to define the trigger strategy. The method can be applied for any final state.

The thesis work concentrated on the developments of selection strategies for the observation of MSSM Higgs bosons in the context of the CMS experiment. The thesis shows, by an example with a MSSM (Minimal Supersymmetric Standard Model) Higgs decaying into two tau, how to define the trigger strategy. The method can be applied for any final state.

No description available.

La thèse décrit une étude de l'état final en paire de leptons tau dans le mode de désintégration semi-leptonique en muons et hadrons en utilisant des données proton-proton collisions à une énergie de centre de masse de 7 TeV avec le détecteur CMS au CERN Large Hadron Collider. La performance de l'algorithme de reconstruction et d'identification des leptons tau est étudiée en utilisant un échantillon de données de collisions proton-proton à $ \ sqrt $ = 7 TeV, ce qui correspond à une luminosité intégrée de 36 pb $ ^ {-1} $. Les leptons tau qui se désintègrent en un seul hadron chargé, avec ou sans hadrons neutres sont reconstruits à l'aide de la technique dite du flot de particules pour la reconstruction des objets en utilisant un nouvel algorithme adapté aux leptons tau et appelé le Hadrons Plus Strips (HPS) qui utilise le trajectographe et le calorimètre électromagnétique de CMS. L'efficacité de l'algorithme de reconstruction est mesurée en utilisant les leptons taus produits lors de la désintégration de bosons Z. Le taux de mauvaise identification de leptons tau se désintégrant de manière hadronique pour les jets produits en association avec un boson W est également déterminé. La première mesure inclusive de production Z $ \ rightarrow \ tau \ tau $ dans les collisions pp au le LHC est présentée dans les états finals muon+jets en utilisant un échantillon de données de 36 pb $ ^ {-1} $. La section efficace mesurée est en bon accord avec les prédictions QCD à l'ordre doublement suivant l'ordre dominant (NNLO). Après avoir identifié le boson Z dans le mode de désintégration di-tau, une recherche inclusive de bosons de Higgs neutres du modèle supersymétrique standard minimal (MSSM) dans les collisions pp est réalisée à une énergie dans le centre de masse de 7 TeV. Les résultats sont basés sur un échantillon de données correspondant à une luminosité intégrée de 36 pb $ ^ {-1} $ et de 4,6 $ fb ^ {-1} $ enregistré par l'expérience CMS dans l'année 2010 et 2011 respectivement. La recherche utilise les désintégrations de bosons de Higgs en paire de leptons tau. Aucun excès n'est observée dans le spectre de masse invariante de paires de leptons tau. Les limites supérieures sur le produit de la section efficace de production de boson de Higgs par le rapport de branchement de la désintégration en paire de leptons tau en fonction de la masse du boson de Higgs pseudoscalaire permettent de donner des limites strictes dans l'espace des paramètres du MSSM. / The thesis describes a study of the tau-pair final state in the semi-leptonic decay mode into muon and hadrons using proton-proton collisions data at a center-of-mass energy of 7 TeV using the CMS detector at the CERN Large Hadron Collider. The performance of tau-lepton reconstruction and identification algorithm is studied using a data sample of proton-proton collisions at $\sqrt{s}$ = 7 TeV, corresponding to an integrated luminosity of 36 pb$^{-1}$. The tau leptons that decay into one charged hadron with or without the association of neutral hadrons is reconstructed using Particle-Flow object reconstruction technique with a novel tau identification algorithm called the Hadron Plus Strips (HPS) algorithm in the CMS tracker and electromagnetic calorimeter. The reconstruction efficiency of the algorithm is measured using $\tau$ leptons produced in Z-boson decays. The hadronically decaying tau lepton misidentification rate for jets produced in association with a W boson is also determined. The first measurement of inclusive Z$\rightarrow\tau\tau$ production in pp collisions at the LHC is presented in muon+hadrons final state using a data sample of 36 pb$^{-1}$. The measured cross-section is in good agreement with the next-to-next-to-leading order (NNLO) QCD prediction. After establishing the Z boson in di-tau decay mode, an inclusive search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions is performed at a center-of-mass energy of 7 TeV. The results are based on a data sample corresponding to an integrated luminosity of 36 pb$^{-1}$ and 4.6 fb$^{-1}$ recorded by the CMS experiment in the year 2010 and 2011 respectively. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross-section times the branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent bounds in the MSSM parameter space.

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.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresenta-se neste trabalho um estudo sobre a largura de decaimento total do bóson de Higgs através do canal H&#8594; ZZ &#8594; (4e, 4, 2e2). Segundo o Modelo Padrão da Física de Partículas Elementares, um bóson de Higgs com massa de 126 GeV deve ter uma largura de decaimento total &#915;H = 4.15 MeV, muito abaixo da resoluções dos experimentos instalados no LHC. Isto impede uma medida direta sobre os eventos da ressonância. Recentemente foi proposto limitar &#915;H a partir da relação entre a taxa de eventos observados na região da ressonância e na região off-shell. Utilizando o pacote de análise desenvolvido pela colaboração CMS obteve-se um limite de &#915;H < 31.46(12.82) MeV em 95(68.3)% CL combinando os dados coletados pelo LHC em colisões pp em &#8730;s = 7 TeV (5.1fb-1) e em &#8730;s = 8 TeV (19.7fb -1). / We present in this work a study about the Higgs boson total width using the channel H&#8594; ZZ &#8594; (4e, 4, 2e2. According to the Standard Model of Elementary Particle Physics, the Higgs boson with mass around 126 GeV should have a total decay width of &#915;H = 4.15 MeV, very below the resolution of the experiments installed at the LHC. This fact prevents a direct measurement on the events of the Higgs resonance. Recently it was proposed limit &#915;H from the relationship between the rate of events observed in the resonance and the off-shell regions. Using the package of analysis developed by CMS collaboration was obtained a limit of &#915;H < 31.46(12.82)MeV in 95(68.3)% CL combining the data collected by the LHC in pp collisions at &#8730;s = 7 TeV (5.1fb-1)and at &#8730;s = 8 TeV (19.7fb -1).

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apresenta-se neste trabalho um estudo sobre a largura de decaimento total do bóson de Higgs através do canal H&#8594; ZZ &#8594; (4e, 4, 2e2). Segundo o Modelo Padrão da Física de Partículas Elementares, um bóson de Higgs com massa de 126 GeV deve ter uma largura de decaimento total &#915;H = 4.15 MeV, muito abaixo da resoluções dos experimentos instalados no LHC. Isto impede uma medida direta sobre os eventos da ressonância. Recentemente foi proposto limitar &#915;H a partir da relação entre a taxa de eventos observados na região da ressonância e na região off-shell. Utilizando o pacote de análise desenvolvido pela colaboração CMS obteve-se um limite de &#915;H < 31.46(12.82) MeV em 95(68.3)% CL combinando os dados coletados pelo LHC em colisões pp em &#8730;s = 7 TeV (5.1fb-1) e em &#8730;s = 8 TeV (19.7fb -1). / We present in this work a study about the Higgs boson total width using the channel H&#8594; ZZ &#8594; (4e, 4, 2e2. According to the Standard Model of Elementary Particle Physics, the Higgs boson with mass around 126 GeV should have a total decay width of &#915;H = 4.15 MeV, very below the resolution of the experiments installed at the LHC. This fact prevents a direct measurement on the events of the Higgs resonance. Recently it was proposed limit &#915;H from the relationship between the rate of events observed in the resonance and the off-shell regions. Using the package of analysis developed by CMS collaboration was obtained a limit of &#915;H < 31.46(12.82)MeV in 95(68.3)% CL combining the data collected by the LHC in pp collisions at &#8730;s = 7 TeV (5.1fb-1)and at &#8730;s = 8 TeV (19.7fb -1).

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 &#8594; bbqq&#956;&#957;&#956;). 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 (bbqq&#956;&#957;&#956;). 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.

Cette thèse présente la première investigation expérimentale de la diffusion des bosons massifs (VBS) dans le canal ZZ où les deux bosons de Z se désintégrés en muons où électrons et sont associées avec deux jets hadroniques (ZZjj->lll’l’jj, l=e,mu). VBS constitue un processus clé dans la compréhension de la physique de la brisure de la symétrie électrofaible et le rôle du boson de Higgs découvert en 2012. Cette étude exploite 35.9fb-1 des collisions proton-proton enregistrés avec le détecteur CMS au Grand collisionneur des hadrons (LHC) à sqrt(s) = 13 TeV. Une analyse multivarié (MVA) est utilisée pour séparer le signal électrofaible du bruit de fond irréductible QCD et pour mesurer la force du signal mu, c'est-à-dire le quotient des nombres d'événements observés et celles attendues. La force du signal observé est de mu = 1.39 (+0.86 -65) et exclut l'hypothèse de l'absence d’un signal à 2.7 écart type (1.6 écart type attendue). Des limites sur la physique au-delà du modèle standard sont dérivés sur les couplages quartiques anomaux dans le cadre de la théorie des champs effectifs (EFT), résultant dans les limites les plus rigoureux sur les couplages des opérateurs T8 et T9.L’analyse VBS dans le canal ZZjj demande une modélisations exacte du signal et du bruit de fond irréductible, exigeant des nouveaux simulations. Des efforts intensifs sur la génération et comparaison des prédictions théoriques de plusieurs générateurs d'événements MC est présenté. La compréhension détaillée du signal et des bruit des fonds sont exploités pour développer et optimiser de façon systématique un arbre de décision boosté (BDT). Un classificateur basé sur les éléments de matrices et également développé et sa puissance comparé aux BDT, montrant des performances identiques. La technique d’extraction du signal par un fit des templates de tous les événements permets d’aussi contraindre la normalization du bruit de fond QCD par les données.Des analyses à quatre leptons comme la recherche pour le processus VBS dans le canal ZZ dépend de la capacité de reconstruire et identifier de façon efficace les leptons dans l'état final. Cette thèse présente des optimisations du algorithme multivarié d’identification des électrons utilisé dans les premiers données à 13 TeV en 2015. L'exploitation des variables liées aux traces des électrons permette une réduction de 50% du bruit de fond des électrons non-prompt. En suivant les changements dans la reconstruction des électrons et grâce à une optimisation continue des algorithmes, la performance dans l'identification des électrons a été maintenue pour les donnés enregistrés en 2016 malgré l’empilement plus sévère. La mesure d'efficacité de sélection d'électrons utilisées pour tous les études à multi-leptons dans CMS sont également documenté. / This thesis reports the first experimental investigation into vector boson scattering (VBS) in the the ZZ channel, where both Z bosons are required to decay into electrons or muons and are accompanied by at least two hadronic jets (ZZjj->lll’l’jj, l=e,mu). VBS is a key process in the elucidating the physics of electroweak symmetry breaking and the role of the recently discovered Higgs boson. The study analyses 35.9fb-1 of proton-proton collisions collected with the CMS experiment at the CERN Large Hadron Collider at a center-of-mass energy of 13 TeV. A multivariate analysis (MVA) technique is exploited to separate the electroweak signal from the QCD irreducible background and to measure the signal strength mu, that is the ratio of the observed number of events to the standard model expectation. The observed signal strength is mu = 1.39 (+0.86 -65) which excludes the background-only hypothesis at 2.7 standard deviations (1.6 standard deviations expected). Limits on physics beyond the standard model are derived in terms of anomalous quartic gauge couplings in the effective field theory approach, providing the most stringent constraints to date on the couplings for the operators T8 and T9.The ZZjj VBS analysis requires an accurate modelling of the signal and irreducible background processes, going beyond the existing simulations. Extensive work on generating and comparing the theory predictions from several MC event generators is presented. The detailed understanding of the signal and background kinematics is used to develop and systematically optimize a boosted decision tree (BDT) classifier. A matrix-element discriminant is also developed and its classification performance compared to the BDT, finding comparable performance and indicating that the BDT is adequate. The final signal extraction technique via a template fit of all ZZjj events is designed to simultaneously constrain the normalization of the QCD background using the data.Multi-lepton analyses like the search for VBS in the ZZ channel depend on the ability to efficiently reconstruct and identify the final state leptons. This work presents the optimizations on the multivariate electron identification algorithms used in the first data at 13 TeV in 2015. A study on extending the use of tracking information in the MVA resulted in the reduction of the non-prompt electron background by up to 50%. Monitoring changes to the reconstructed electron objects and continuous optimizations allowed to improve or maintain the performance of the electron MVA ID algorithms, despite the harsher pile-up conditions in the 2016 data. The electron efficiency measurements used by the 2016 multi-lepton analyses in CMS are also documented.