Measurement of the Higgs boson mass in the $H \rightarrow ZZ^* \rightarrow 4\ell$ decay channel with $\sqrt{s}=13$ TeV $pp$ collisions using the ATLAS detector at the LHC

A measurement of the Higgs boson mass, $m_H$ in the $H \rightarrow ZZ^* \rightarrow 4\ell$ decay channel is presented. The data employed were recorded by the ATLAS detector between 2015-2018 in proton-proton collisions delivered by the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=13$ TeV and correspond to an integrated luminosity of $139~\text{fb}^{-1}$. An analytic model that takes into account the invariant mass resolution of the four-lepton system on a per-event basis is employed. The measured value of $m_H$ is $124.92\pm0.19\text{(stat.)}^{+0.09}_{-0.06}\text{(syst.)}$~GeV.