TY - JOUR T1 - Search for top quark decays \(t → qH\), with \(H → γγ\), in \(\sqrt{s} = 13\) TeV \(pp\) collisions using the ATLAS detector JF - Journal of High Energy Physics N2 - This article presents a search for flavour-changing neutral currents in the decay of a top quark into an up-type (\({q = c, u}\)) quark and a Higgs boson, where the Higgs boson decays into two photons. The proton-proton collision data set analysed amounts to 36.1 fb\(^{−1}\) at \(\sqrt{s} = 13\) TeV collected by the ATLAS experiment at the LHC. Top quark pair events are searched for, where one top quark decays into \(qH\) and the other decays into \(bW\). Both the hadronic and leptonic decay modes of the \(W\) boson are used. No significant excess is observed and an upper limit is set on the \({t → cH}\) branching ratio of 2.2 × 10\(^{−3}\) at the 95% confidence level, while the expected limit in the absence of signal is 1.6 × 10\(^{−3}\). The corresponding limit on the \(tcH\) coupling is 0.090 at the 95% confidence level. The observed upper limit on the \({t → uH}\) branching ratio is 2.4 × 10\(^{−3}\). KW - High energy physics KW - Flavour changing neutral currents KW - Hadron-Hadron scattering (experiments) KW - Higgs physics KW - Top physics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172568 VL - 2017 IS - 10 ER -