Search for flavor changing neutral currents in decays of top quarks

Collaboration, D0 and Bertram, Iain and Borissov, Guennadi and Fox, Harald and Ross, Anthony and Williams, Mark and Ratoff, Peter (2011) Search for flavor changing neutral currents in decays of top quarks. Physics Letters B, 701 (3). pp. 313-320.

Abstract

We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for ttbar -> l'null + jets (l, l' = e, mu) final states using 4.1 fb^-1 of integrated luminosity of ppbar collisions at sqrt(s) = 1.96 TeV. We extract limits on the branching ratio B(t -> Zq) (q = u, c quarks), assuming anomalous tuZ or tcZ couplings. We do not observe any sign of such anomalous coupling and set a limit of B