Search for the decay of a heavy Higgs boson $\text{H}$ into two lighter Higgs bosons $\text{h}$ and $\text{h}_{\text{S}}$ in the $\text{h}(\tau\tau)\text{h}_{\text{S}}(\text{bb})$ final state at $13\,\text{TeV}$

A search for the decay of a heavy Higgs boson $\text{H}$ into the observed Higgs boson $\text{h}$ and another Higgs boson $\text{h}_{\text{S}}$ with a mass of $m_{\text{h}_{\rm S}} < m_{\text{H}} - m_{\text{h}}$ is presented. The $\text{h}$ and $\text{h}_{\text{S}}$ bosons are required to decay into a pair of tau leptons and a pair of $\text{b}$ quarks, respectively. The search uses $137\,\text{fb}^{-1}$ of proton-proton collisions collected with the CMS detector at a center-of-mass energy of $13\,\text{TeV}$. A mass range of $240 - 3000\,\text{GeV}$ for $m_{\text{H}}$ and $60 - 2800\,\text{GeV}$ for $m_{\text{h}_{\text{S}}}$ is covered. No signal has been observed. Therefore, model independent $95\%$ confidence level upper limits on the product of the production cross section and the branching fractions of the signal process are set ranging from $125\,\text{fb}$ (for $m_{\text{H}}=240\,\text{GeV}$) to $2.7\,\text{fb}$ (for $m_{\text{H}}=3000\,\text{GeV}$). These limits are compared to predictions of the next-to-minimal supersymmetric extension of the standard model.