Searches For Heavy Resonances In The $R \rightarrow WW \rightarrow \ell\nu\ell\nu$ Decay Channel Using $pp$ Collisions At $\sqrt{s}$ = 13 TeV With The ATLAS Detector At The LHC

This thesis presents a search for a heavy Higgs-like resonance decaying in the $R \rightarrow WW^{*} \rightarrow \ell\nu\ell\nu$ channel using the ATLAS detector at the Large Hadron Collider. The search uses proton-proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 139 fb$^{-1}$. Interpretations are given under the narrow-width approximation, Georgi-Machacek model, the radion particle of the Randall-Sundrum graviton model, a HVT model, and a spin-2 graviton of the Randall-Sundrum model.