Speaker
Description
Photophobic axion-like particles (ALPs) have suppressed couplings to diphotons but can still interact with electroweak gauge bosons. In this talk, we investigate the discovery prospects for heavy photophobic ALPs at the High-Luminosity Large Hadron Collider (HL-LHC, $\sqrt{s}=14$ TeV) and a future 100 TeV proton–proton collider, with particular emphasis on the latter. Assuming a vanishing diphoton coupling, $g_{a\gamma\gamma}=0$, we investigate three complementary signal channels: $Z\gamma jj$, $W^\pm W^\pm W^\mp$, and $W^+W^-jj$, including $s$-channel and vector-boson-fusion (VBF) production mechanisms where applicable. Monte Carlo simulations, detector-level event selections, and boosted decision tree (BDT) multivariate analyses are employed to distinguish the signals from Standard Model backgrounds. In addition to the main analysis, we discuss representative kinematic distributions, reconstruction observables, BDT responses, and selection efficiencies presented in the appendices, together with considerations relevant to the robustness and interpretation of the results.The results indicate that a 100 TeV proton–proton collider can substantially improve the sensitivity to $g_{aWW}$ and extend the ALP mass range, with different signal channels providing complementary discovery opportunities.
