Search for FCNC single top-quark production at √s = 7 TeV with the ATLAS detector
A search for the production of single top-quarks via flavour-changing neutral-currents is presented. Data collected with the ATLAS detector at a centre-of-mass energy of √s = 7 TeV, corresponding to an integrated luminosity of 2.05 fb<sup>-1</sup>, are used. Candidate events with a semil...
Guardado en:
| Autores principales: | , , , , |
|---|---|
| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2012
|
| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/80315 |
| Aporte de: |
| Sumario: | A search for the production of single top-quarks via flavour-changing neutral-currents is presented. Data collected with the ATLAS detector at a centre-of-mass energy of √s = 7 TeV, corresponding to an integrated luminosity of 2.05 fb<sup>-1</sup>, are used. Candidate events with a semileptonic top-quark decay signature are classified as signal- or background-like events by using several kinematic variables as input to a neural network. No signal is observed in the neural network output distribution and a Bayesian upper limit is placed on the production cross-section. The observed upper limit at 95% confidence level on the cross-section multiplied by the t → Wb branching fraction is measured to be σ<sub>qg→t</sub> × B(t → Wb) < 3.9 pb. This upper limit is converted using a model-independent approach into upper limits on the coupling strengths κ<sub>ugt</sub>/Λ < 6.9 · 10<sup>-3</sup> TeV<sup>-1</sup> and κ<sub>cgt</sub>/Λ < 1.6 · 10<sup>-2</sup> TeV<sup>-1</sup>,where Λ is the new physics scale, and on the branching fractions B(t → ug) < 5.7 · 10<sup>-5</sup> and B(t → cg) < 2.7 · 10<sup>-4</sup>. |
|---|