A direct search for lepton-flavour-violating decays of a Higgs boson (mH = 125 GeV) is described. The search is performed for the H→eτμ, H→eτh, and H→eμ decays, where τh and τμ are taus reconstructed in the hadronic and muonic decay channels, respectively. The data sample used in the search corresponds to an integrated
luminosity of 19.7 fb−1 collected in pp collisions at s=8 TeV with the CMS experiment at the CERN LHC. No evidence is found for lepton-flavour-violating decays in either final state. For the H→eτμ and H→eτh channels, the sensitivity of the search is an order of magnitude better than the existing indirect limits. A constraint of B(H→eτ)<0.70% at 95% confidence level is set. We also set a limit on the branching ratio of B(H→eμ)<0.036% at 95% confidence level.
The limits on B(H→eτ) and B(H→eμ) are subsequently used to constrain the ∣Yeτ∣ and ∣Yeμ∣ Yukawa couplings.