Search for the standard model Higgs boson in $\mathrm{H}\to \mathrm{ZZ}\to \ell^+\ell^-\tau^+\tau^-$ decay channel with the CMS experiment at $\sqrt{s}=$ 7 and 8 TeV

A search for the standard model Higgs boson in the decay mode $\mathrm {H}\to \mathrm {ZZ}\to \ell^+ \ell^-\tau^+\tau^-$ ($\ell = e, \mu$) is presented. The analysis uses the proton-proton collision data recorded by the CMS experiment at the LHC, corresponding to integrated luminosity of 5.1 fb$^{-1}$ at $\sqrt{s}=$ 7 TeV and 12.2 fb$^{-1}$ at $\sqrt{s}=$ 8 TeV. Both the hadronic and leptonic decays of $\tau$ are inspected. No evidence is found for a significant deviation from the standard model expectations anywhere in the ZZ mass range considered in this analysis. An upper limit at 95\% confidence level is placed on product of the cross-section and decay branching ratio for the Higgs boson decaying with standard model like couplings, which excludes the cross-sections of about two to four times the expected values for the Higgs boson masses in the range of $190<m\mathrm{_H}<600$ GeV/c$^2$.