Measurement of the tt¯ production cross-section using eμ events with b-tagged jets in pp collisions at s=13TeV with the ATLAS detector
Number of Authors: 2855
2016 (English)In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 761, 136-157 p.Article in journal (Refereed) Published
This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2fb−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.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 761, 136-157 p.
IdentifiersURN: urn:nbn:se:kth:diva-197693DOI: 10.1016/j.physletb.2016.08.019ScopusID: 2-s2.0-84983541807OAI: oai:DiVA.org:kth-197693DiVA: diva2:1052947
QC 201612072016-12-072016-12-072016-12-07Bibliographically approved