Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment

, The ATLAS collaboration (2016) Measurement of the charge asymmetry in highly boosted top-quark pair production in √s=8 TeV pp collision data collected by the ATLAS experiment. Physics Letters B, 756. pp. 52-71. ISSN 0370-2693

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Abstract

In the pp → tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at √s = 8 TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯ > 0.75 TeV) and an absolute rapidity difference of the top and anti-top quark candidates within −2 < |yt| − |yt¯| < 2 is measured to be 4.2 ± 3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.

Item Type:
Journal Article
Journal or Publication Title:
Physics Letters B
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3106
Subjects:
ID Code:
79617
Deposited By:
Deposited On:
17 May 2016 15:10
Refereed?:
Yes
Published?:
Published
Last Modified:
26 Nov 2020 03:55