Search for high mass resonances decaying into $\mathrm{W^+}\mathrm{W^-}$ in the dileptonic final state with $138\,\text{fb}^{-1}$ of proton-proton collisions at $\sqrt{s}=13\,\text{TeV}$

A search for high mass resonances decaying into a pair of W bosons is performed. The analysis considers the fully leptonic final state ($\mathrm{e}\mu$, $\mu\mu$, $\mathrm{e}\mathrm{e}$). New techniques are implemented in the analysis to improve the sensitivity of the search, especially in the very high mass range. The search is performed in a mass range from $115\,\text{GeV}$ to $5\,\text{TeV}$, and for various width hypotheses. Both the gluon-gluon-fusion and vector-boson-fusion signal production processes are considered. Interference effects between signal and background are also taken into account. The results are presented as $95\%$ confidence level upper limits on the product of the cross section and branching ratio on the production of a high mass resonance, and exclusion limits are derived on various two-higgs-doublet models and minimal supersymmetric standard model benchmark scenarios.