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 sqrt(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.
Search for flavour-changing neutral current top-quark decays to qZ in pp collision data collected with the ATLAS detector at sqrt(s) = 8 TeV
CHIODINI, GABRIELE;GORINI, Edoardo;PRIMAVERA, Margherita;SPAGNOLO, Stefania Antonia;VENTURA, Andrea
2016-01-01
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 sqrt(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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
