Publicação
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at root s=7 TeV with the ATLAS experiment
| Resumo: | This paper describes an analysis of the angular distribution of W→eν and W→μν decays, using data from pp collisions at √s=7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb−1. Using the decay lepton transverse momentum and the missing transverse momentum, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (pWT):35<pWT<50 GeV and pWT>50 GeV. Good agreement is found with theoretical predictions. For pWT>50 GeV, the values of f0 and fL−fR, averaged over charge and lepton flavour, are measured to be: f0=0.127±0.030±0.108 and fL−fR=0.252±0.017±0.030, where the first uncertainties are statistical, and the second include all systematic effects. |
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| Autores principais: | Onofre, A. |
| Outros Autores: | Castro, Nuno Filipe Silva Fernandes; ATLAS Collaboration |
| Assunto: | Ciências Naturais::Ciências Físicas Ciências Naturais::Ciências Físicas |
| Ano: | 2012 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | This paper describes an analysis of the angular distribution of W→eν and W→μν decays, using data from pp collisions at √s=7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb−1. Using the decay lepton transverse momentum and the missing transverse momentum, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (pWT):35<pWT<50 GeV and pWT>50 GeV. Good agreement is found with theoretical predictions. For pWT>50 GeV, the values of f0 and fL−fR, averaged over charge and lepton flavour, are measured to be: f0=0.127±0.030±0.108 and fL−fR=0.252±0.017±0.030, where the first uncertainties are statistical, and the second include all systematic effects. |
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