T 65.6: Vortrag
Mittwoch, 11. März 2015, 18:00–18:15, L.10.31 (HS 10)
Measurement of the charge asymmetry in dileptonic tt events at √s=7 TeV using the ATLAS detector — Sara Borroni1, Nello Bruscino2, Markus Cristinziani2, Frédéric Déliot3, Cécile Deterre1, Mazuza Ghneimat2, Sebastian Heer2, Vadim Kostyukhin2, Roman Lysák4, Evan Machefer2, •Liza Mijović2,3, Reinhild Yvonne Peters5, Ralf Schäfer1, and Kaven Yau Wong2 — 1DESY, Hamburg — 2Physikalisches Institut, Universität Bonn — 3CEA, Saclay — 4Acad. of Sciences of the Czech Rep. — 5University of Manchester
A measurement of the top-antitop (tt) charge asymmetry is
presented using data corresponding to an integrated luminosity of
4.6 fb−1 of LHC pp collisions at a centre-of-mass energy
of 7 TeV collected by the ATLAS detector. Events with two charged leptons,
at least two jets and missing transverse momentum are selected. Two charge
asymmetry observables are studied, based on the identified charged
leptons, ACℓℓ, or on the reconstructed
tt final state, ACtt. The asymmetries are measured to be:
| ACℓℓ | = | 0.024 ± 0.015 (stat.) ± 0.009 (syst.), |
|
| ACtt | = | 0.021 ± 0.025 (stat.) ± 0.017 (syst.). |
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The measured values are in agreement with the Standard Model predictions.