Publicação
Measurement of the gamma(1S) production cross-section in pp collisions at root s=7 TeV in ATLAS
| Resumo: | A measurement of the cross-section for ϒ(1S)→μ+μ−ϒ(1S)→μ+μ− production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the ϒ(1S)ϒ(1S) transverse momentum in two bins of rapidity, |yϒ(1S)|<1.2|yϒ(1S)|<1.2 and 1.2<|yϒ(1S)|<2.41.2<|yϒ(1S)|<2.4. The measurement requires that both muons have transverse momentum View the MathML sourcepTμ>4 GeV and pseudorapidity |ημ|<2.5|ημ|<2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb−1, collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model. |
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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: | 2011 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | A measurement of the cross-section for ϒ(1S)→μ+μ−ϒ(1S)→μ+μ− production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the ϒ(1S)ϒ(1S) transverse momentum in two bins of rapidity, |yϒ(1S)|<1.2|yϒ(1S)|<1.2 and 1.2<|yϒ(1S)|<2.41.2<|yϒ(1S)|<2.4. The measurement requires that both muons have transverse momentum View the MathML sourcepTμ>4 GeV and pseudorapidity |ημ|<2.5|ημ|<2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb−1, collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model. |
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