Combined multilepton and diphoton limit on t to cH

Based on the CMS inclusive multilepton analysis and a CMS 2HDM search involving lepton and photon final states, we present a $95\,\%$ CL limit on the branching ratio of the flavor-changing decay ${\rm t}\to{\rm c}\textrm{H}$. The data sample corresponds to $19.5\,\textrm{fb}^{-1}$ of integrated luminosity in pp collisions at $\sqrt{s} = 8\,\textrm{TeV}$ collected by the CMS experiment at the LHC in 2012. We find that $\mathcal{B}({\rm t}\to{\rm c}\textrm{H}) < 0.56\,\%$, corresponding to a bound on the left- and right-handed top-charm flavor violating Higgs Yukawa couplings of $\sqrt{|\lambda_{{\rm tc}}^\textrm{H}|^2 + |\lambda_{{\rm ct}}^\textrm{H}|^2} < 0.14$. The observed bound is consistent with the expected bound of $0.65\,\%$.