Search for flavour-changing neutral current top-quark decays to qZ in pp collision data collected with the ATLAS detector at √s=8 TeV


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Aad G., Abbott B., Abdallah J., Abdinov O., Aben R., Abolins M., ...More

European Physical Journal C, vol.76, no.1, pp.1-24, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 76 Issue: 1
  • Publication Date: 2016
  • Doi Number: 10.1140/epjc/s10052-015-3851-5
  • Journal Name: European Physical Journal C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-24
  • Ankara University Affiliated: Yes

Abstract

A search for the flavour-changing neutral-current decay t→qZ is presented. Data collected by the ATLAS detector during 2012 from proton–proton collisions at the Large Hadron Collider at a centre-of-mass energy of √s=8 TeV, corresponding to an integrated luminosity of 20.3 fb-1, are analysed. Top-quark pair-production events with one top quark decaying through the t→qZ (q=u,c) channel and the other through the dominant Standard Model mode t→bW are considered as signal. Only the decays of the Z boson to charged leptons and leptonic W boson decays are used. No evidence for a signal is found and an observed (expected) upper limit on the t→qZ branching ratio of 7×10-4 (8×10-4) is set at the 95 % confidence level