| Popis: |
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 a√t 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 peerReviewed |
