Effective field theory interpretation of the measurement of off-shell Higgs boson production from $ZZ \rightarrow 4\ell$ and $ZZ \rightarrow 2\ell2\nu$ decay channels with the ATLAS detector

This note reports on the effective field theory (EFT) interpretation of the measurement of off-shell Higgs boson production using 139 fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of 13 TeV, collected by the ATLAS detector at the Large Hadron Collider. Higgs boson decays to $ZZ \rightarrow 4\ell$ and $ZZ \rightarrow 2\ell2\nu$ final states, with $\ell = e $ or $\mu$, are considered. Off-shell Higgs boson events with masses of the order of 1 TeV are sensitive to phenomena beyond the Standard Model. Furthermore, the Higgs boson coupling to the top quark and its effective coupling to the gluon are degenerate in the inclusive on-shell measurements while the off-shell events can break the degeneracy. EFT operators affecting these couplings are studied and their associated Wilson coefficients are observed (expected) to be [-9, 18] ([-9, 17]) for $c_{t\varphi}$ (Higgs-top coupling modifier) and [-0.04, 0.03] ([-0.04, 0.03]) for $c_{\varphi G}$ (Higgs-gluon coupling modifier) at the 95$\%$ confidence level with new physics energy scale $\Lambda = 1$ TeV, in agreement with the SM prediction.