Resonant Di-Higgs Searches in $b\bar{b}{\tau }^{+}{\tau }^{-}$ at HL-LHC: Supersymmetry versus Compositeness Benchmarks

We explore the scope of the High-Luminosity Large Hadron Collider (HL-LHC) in testing Standard Model (SM) di-Higgs production and decay into $2b2\tau$ final states in the context of two viable theories of the Electro-Weak (EW) scale: Supersymmetry and Compositeness. Specifically, we target minimal model realisations of these two scenarios that enable the resonant process $gg\to H\to hh\to b\bar{b}{\tau }^{+}{\tau }^{-}$, where $h$ is the SM-like Higgs state and $H$ a heavier CP-even companion, with the $\tau$’s decaying hadronically. This is realised within the Next-to-Minimal Supersymmetric SM and the Composite 2-Higgs Doublet Model, respectively. Using two illustrative benchmark points, after performing a thorough detector-level Monte Carlo (MC) analysis exploiting new observables, we show that, in the former case, there is more moderate sensitivity, owing to large backgrounds, whereas, in the latter case, substantial scope for discovery exists, in a background free environment.