Measurement of the t-channel single top-quark production cross section in pp collisions at √s = 7 TeV with the ATLAS detector
We report a measurement of the cross section of single top-quark production in the t-channel using 1.04 fb<sup>-1</sup> of pp collision data at √s = 7 TeV recorded with the ATLAS detector at the LHC. Selected events feature one electron or muon, missing transverse momentum, and two or th...
| Autores: | , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2012 |
| País: | Argentina |
| Recursos: | Universidad Nacional de La Plata |
| Repositório: | SEDICI (UNLP) |
| Idioma: | inglês |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/80331 |
| Acesso em linha: | http://sedici.unlp.edu.ar/handle/10915/80331 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Ciencias Exactas Física top quark ATLAS detector la̵rge hadron collider |
| Resumo: | We report a measurement of the cross section of single top-quark production in the t-channel using 1.04 fb<sup>-1</sup> of pp collision data at √s = 7 TeV recorded with the ATLAS detector at the LHC. Selected events feature one electron or muon, missing transverse momentum, and two or three jets, exactly one of them identified as originating from a b quark. The cross section is measured by fitting the distribution of a multivariate discriminant constructed with a neural network, yielding σ<sub>t</sub>= 83±4(stat.)<sup>+20</sup><sub>-19</sub>(syst.) pb, which is in good agreement with the prediction of the Standard Model. Using the ratio of the measured to the theoretically predicted cross section and assuming that the top-quark-related CKM matrix elements obey the relation |V<sub>tb</sub>| ≫ |V<sub>ts</sub>|,|V<sub>td</sub>|, the coupling strength at the W-t-b vertex is determined to be |V<sub>tb</sub>|=1.13<sup>+0.14</sup><sub>-0.13</sub>. If it is assumed that |V<sub>tb</sub>| ≤ 1 a lower limit of |V<sub>tb</sub>| > 0.75 is obtained at the 95% confidence level. |
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