Understand
Results are presented from a search for the Higgs boson decay H $\to$ Z$\gamma$, where Z $\to$ $\ell^+\ell^-$ with $\ell$ = e or $\mu$.
- The search is performed using a sample of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb$^{-1}$.
- Events are assigned to mutually exclusive categories, which exploit differences in both event topology and kinematics of distinct Higgs production mechanisms to enhance signal sensitivity.
- The signal strength $\mu$, defined as the product of the cross section and the branching fraction [$\sigma($pp $\to$ H$)\mathcal{B}($H $\to$ Z$\gamma)$] relative to the standard model prediction, is extracted from a simultaneous fit to the $\ell^+\ell^-\gamma$ invariant mass distributions in all categories and is found to be $\mu$ = 2.4 $\pm$ 0.9 for a Higgs boson mass of 125.38 GeV.