Measurement of the tt¯tt¯ production cross-section using eμeμ events with b-tagged jets in pp collisions at s√s=13 TeV with the ATLAS detector

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  • Authors:
  • ATLAS Collaboration

Abstract

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb¯1 of proton–proton collisions at a centre-of-mass energy of s√=13TeV , collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b -tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be:

σtt¯=818±8(stat)±27(syst)±19(lumi)±12(beam) pb,

where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented.

Bibliographical metadata

Original languageEnglish
Pages (from-to)136-157
Number of pages20
JournalPhysics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume761
DOIs
Publication statusPublished - 16 Aug 2016

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