Measurements of fiducial cross-sections for t ̄t production with one or two additional b-jets in pp collisions at √s = 8 TeV using the ATLAS detector
Fiducial cross-sections for t ̄t production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb<sup>−1</sup> of proton–proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-se...
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| Autores principales: | , , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2016
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/79709 |
| Aporte de: |
| Sumario: | Fiducial cross-sections for t ̄t production with one or two additional b-jets are reported, using an integrated luminosity of 20.3 fb<sup>−1</sup> of proton–proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for t ̄t events with at least one additional b-jet is measured to be 950 ± 70 (stat.) <sup>+240</sup><sub>−190</sub> (syst.) fb in the lepton-plus-jets channel and 50 ± 10 (stat.) <sup>+15</sup><sub>−10</sub> (syst.) fb in the eμ channel. The cross-section times branching ratio for events with at least two additional b-jets is measured to be 19.3 ± 3.5 (stat.) ± 5.7 (syst.) fb in the dilepton chan- nel (eμ,μμ, and ee) using a method based on tight selection criteria, and 13.5 ± 3.3 (stat.) ± 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 ± 0.33 (stat.) ± 0.28 (syst.)% for the ratio of t ̄t production with two additional b-jets to t ̄t production with any two additional jets. All measurements are in good agreement with recent theory predictions. |
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