Update of the prospects for the H → Zγ search at the High-Luminosity LHC

This note documents updated prospects for studies of $H\to Z\gamma$ at the HL-LHC, building on the analysis documented following the European Committee for Future Accelerators workshop in 2013 with the addition of background yield corrections and more sensitive kinematic categories. The ultimate expected reach of the ATLAS experiment, with an integrated luminosity of 3000 $\text{fb}^{-1}$, assuming average pile-up corresponding to $\mu$=140, is discussed in detail, and its intermediate potential with 300 $\text{fb}^{-1}$ and $\mu$=60 is briefly described. Assuming the Higgs boson discovered in 2012 with a mass of 125 GeV to be the Standard Model Higgs boson, the expected local significance is 3.9(2.3) $\sigma$ with 3000(300) $\text{fb}^{-1}$.