Prospects for the study of the Higgs boson in the VH(bb) channel at HL-LHC

This note describes a simulated analysis of Higgs boson production and decay into $b$-quarks in association with a vector boson at the ATLAS detector at the high-luminosity LHC with proton-proton collisions at $\sqrt{s}=14\;\mathrm{TeV}$. The vector bosons are reconstructed from final states including at least one electron or muon: $Z\rightarrow \ell^+\ell^-$ or $W\rightarrow \ell \nu$. The analysis uses generator-level Monte Carlo samples to which efficiency and resolution smearing functions are applied to reproduce the expected resolution of the upgraded ATLAS detector for the expected amount of pile-up due to multiple overlapping proton-proton collisions. The expected significance for $300\;\mathrm{fb}^{-1}$ using an average pile-up of $\langle \mu \rangle_{\mathrm{pu}} = 60$ is $3.9\sigma$ for the combined $ZH(\rightarrow \ell^+\ell^- b\bar{b})$ and $WH(\rightarrow \ell \nu b\bar{b})$ channels, yielding an expected error on the signal strength of $\sim 25\%$. For $3000\;\mathrm{fb}^{-1}$ using an average pile-up of $\langle \mu \rangle_{\mathrm{pu}} =140$ the expected significance is $8.8\sigma$, and the error on the signal strength is expected to be ~15%.