All-hadronic HHZ production at 3 TeV CLIC

In this note, $\mathrm{Z}\mathrm{H}\mathrm{H}$ production in the all-hadronic final state is studied in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ collisions at the Compact Linear Collider at the 3 TeV stage. At this stage this Higgs boson pair production mode is sub-leading to the ${\mathrm{W}}^{+}{\mathrm{W}}^{-}$ fusion production cross-section of ${\mathrm{e}}^{+}{\mathrm{e}}^{-}\to \mathrm{H}\mathrm{H}\nu \nu$. The events are characterised by a topology of six jets, where the masses of the three pair-wise combinations of two jets are compatible with originating from two $\mathrm{H}$ and one $\mathrm{Z}$ bosons. The event selection concentrates on the dominant $\mathrm{H}$ boson decays into two b-quarks by requiring a presence of multiple b-jets. The study is based on full simulation using the CLICdet model, including beam-induced backgrounds from $\gamma \gamma \to \mathrm{h}\mathrm{a}\mathrm{d}\mathrm{r}\mathrm{o}\mathrm{n}\mathrm{s}$. Results on the measurement of the total $\mathrm{Z}\mathrm{H}\mathrm{H}$ cross section are given.