Search for the \(\gamma Z\) decay mode of heavy photophobic axion-like particles at the LHC

We assume the coupling of Axion-like particle (ALP) to diphoton \(g_{a\gamma\gamma} \sim 0\) and accomplish detailed analyses for the \(\gamma Z\) decay mode of such heavy photophobic ALPs at the high luminosity-Large Hadron Collider (HL-LHC). ALPs are produced with two jets via both the \(s\)-channel vector boson exchange and vector boson fusion processes, with the signal process \(pp \to jj\, a (\to \gamma\, Z (\to \ell^+ \ell^-)\, ) \) for \(\ell = e, \mu\). Signal and background events are simulated at the detector-level. Preselection criteria target events with one photon, two oppositely charged electrons or muons, and two non-\(b\)-tagged jets. The ALP mass is reconstructed, and kinematic observables are input into a machine learning-based multivariate analysis for optimal background rejection. Discover sensitivities on the ALP's coupling to di-\(W\) boson, \(g_{aWW}\), are presented in the mass range from 100 to 4000 GeV at center-of-mass energy \(\sqrt{s} = 14\) TeV and integrated luminosity \(\mathcal{L} =\) 3 ab\(^{-1}\) and 140 fb\(^{-1}\). Sensitivities on the production cross section \(\sigma (pp \to jj\, a)\) times the branching ratio Br\((a \to \gamma Z)\) are also presented.