Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/22087
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Saavedra, Juan | - |
dc.contributor.advisor | Gonçalves, António Joaquim Onofre de Abreu Ribeiro | - |
dc.contributor.author | Fiolhais, Miguel Castro Nunes | - |
dc.date.accessioned | 2013-03-08T17:27:16Z | - |
dc.date.issued | 2013-03-07 | - |
dc.identifier.citation | FIOLHAIS, Miguel Castro Nunes - Study of the Wtb vertex structure in top quark decays with the ATLAS experiment and future prospects. Coimbra : [s.n.], 2013 | por |
dc.identifier.uri | https://hdl.handle.net/10316/22087 | - |
dc.description | Tese de doutoramento em Física, na especialidade de Física Experimental, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra | pt |
dc.description.abstract | In this thesis, the ATLAS sensitivity to the Wtb vertex structure was studied in top quark decays. Measurements were performed on the polarization of W± bosons, derived from top quark pairs events (t¯t) with single lepton and dilepton topologies. The results were obtained with data from pp collisions at a center-of-mass energy of 7 TeV, collected by the ATLAS experiment at the Large Hadron Collider (LHC), corresponding to an integrated luminosity of 1.04 fb−1. The measured fractions of the longitudinal, left-handed and right-handed helicities are F0 = 0.67 ± 0.07, FL = 0.32 ± 0.04 and FR = 0.01 ± 0.05, which can be translated into angular asymmetries yielding A+ = 0.53±0.02 and A− = −0.84±0.02. These results are in good agreement with the Standard Model predictions, and correspond in the present date to the most precise published results. As the polarization of the W± bosons in top quark decays is sensitive to the Lorentz structure and couplings of the Wtb vertex, the measurements were used to set limits on anomalous contributions to the Wtb couplings. These results obtained at the LHC were compared with the expected results in a possible future linear collider, such as the International Linear Collider (ILC). The sensitivity to these anomalous couplings may largely surpass the one achievable by the LHC either in neutral or charged current processes. | pt |
dc.description.abstract | Na presente tese ´e discutida a sensibilidade de ATLAS `a estrutura do v´ertice Wtb em decaimentos de quarks top. Para tal, realizaram-se medidas da polariza ¸c˜ao de bos˜oes W±, a partir de eventos de pares de quarks top (t¯t) com topologias de um e dois lept˜oes no estado final. Os resultados foram obtidos com dados de colis˜oes pp, recolhidos pela experiˆencia ATLAS do Large Hadron Collider (LHC), correspondentes a uma luminosidade integrada de 1.04 fb−1, a uma energia de centrode- massa de 7 TeV. As fra¸c˜oes de helicidade longitudinal, esquerda e direita, foram medidas a F0 = 0.67 ± 0.07, FL = 0.32 ± 0.04 e FR = 0.01 ± 0.05, e podem ser traduzidas em assimetrias angulares A+ = 0.53 ± 0.02 e A− = −0.84 ± 0.02. Estes resultados encontram-se em bom acordo com as previs˜oes do Modelo Padr˜ao, e correspondem aos resultados mais precisos publicados at´e `a presente data. Como a polariza¸c˜ao dos bos˜oes W± em decaimentos de quarks top ´e sens´ıvel `a estrutura de Lorentz e aos acoplamentos do v´ertice Wtb, as medidas foram utilizadas para estabelecer limites nas contribui¸c˜oes dos acoplamentos an´omalos do v´ertice Wtb. Estes resultados obtidos em LHC foram comparados com os resultados esperados num poss´ıvel colisionador linear futuro, tal como o International Linear Collider (ILC). A sensibilidade a estes acoplamentos an´omalos poder´a ultrapassar largamente a sensibilidade ating´ıvel em LHC, tanto em processos de corrente carregada como em processos de corrente neutra. v | pt |
dc.language.iso | eng | pt |
dc.relation | 48680 | pt |
dc.rights | openAccess | pt |
dc.title | Study of the Wtb Vertex Structure in Top Quark Decays with the ATLAS experiment and Future Prospects | pt |
dc.type | doctoralThesis | pt |
dc.peerreviewed | yes | pt |
thesis.degree.name | Doutoramento em Física, na especialidade de Física Experimental | pt |
uc.rechabilitacaoestrangeira | no | pt |
item.languageiso639-1 | en | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.grantfulltext | open | - |
item.fulltext | Com Texto completo | - |
item.cerifentitytype | Publications | - |
item.openairetype | doctoralThesis | - |
crisitem.advisor.orcid | 0000-0002-7238-9647 | - |
crisitem.author.researchunit | LIP – Laboratory of Instrumentation and Experimental Particle Physics | - |
Appears in Collections: | FCTUC Física - Teses de Doutoramento |
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File | Description | Size | Format | |
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Study of the Wtb Vertex Structure in Top Quark Decays.pdf | 7.14 MB | Adobe PDF | View/Open |
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