Search for a Higgs boson decaying to a pair of 125 GeV Higgs bosons (\textit{hh}) or for a Higgs boson decaying to \textit{Zh}, with $\tau$- leptons in the final state

A search for heavy Higgs boson (\textit{H}) decaying into a pair of lighter (Standard Model like) 125 GeV Higgs bosons (\textit{h}) or a Higgs boson (\textit{A}) decaying into a \textit{Z} boson and an \textit{h} boson is presented. This search is performed on a dataset corresponding to an integrated luminosity of 19.7 fb\textsuperscript{-1} of pp collision data collected by CMS in 2012 at $\sqrt{s} =$ 8 TeV. A final state consisting of two $\tau$- leptons and two $b$-jets is used to search for the \textit{H} $\rightarrow$ \textit{hh} mode while a final state consisting of two $\tau$-leptons and two additional light leptons (electrons/muons), the latter compatible with the decay products of a \textit{Z} boson, is used to search for the \textit{A} $\rightarrow$ \textit{Zh} mode. This search is performed in the context of two benchmark scenarios: one of the minimal supersymmetric extension to the standard model and other of a two Higgs Doublet Model. No excess is found and upper limits at 95 $\%$ confidence level are set on the production cross-section in the mass range 220 GeV to 350 GeV for the Higgs boson \textit{A} and 260 GeV to 350 GeV for the Higgs boson \textit{H}.