Unstable Z bosons, leptons, ATLAS, CMS, Signal Reported, Effects of new theories

Recently, the ATLAS and CMS collaborations reported an excess of events in the decay $H \rightarrow Z\gamma$, where the signal reported by both collaborations is $\mu^{Z\gamma} = 2.2 \pm 0.7$. This is more than twice the Standard Model prediction. Therefore, the explanation for this result could come from new physics theories. In particular, in this work, we are interested in contributions related to CP symmetry violation, which could have an impact on the three-body decay of the Higgs: $H \rightarrow Z\gamma \rightarrow \ell^- \ell^+ \gamma$. We propose to study the effects of new theories that can be measured at the LHC, with the aim of determining whether these models are valid or can be discarded. In this way, we will be closer to finding a final theory that describes the behavior of the universe.