Search for heavy resonances decaying into a $W$ boson and a Higgs boson in final states with leptons and $b$-jets in $139~fb^{-1}$ of $pp$ collisions at $\sqrt{s}=13~\mathrm{TeV}$ with the ATLAS detector

This poster presents a search for a new resonance $W^\prime$ decaying into a $W$ boson and a $125~\mathrm{GeV}$ Higgs boson $H$ in the $\ell\nu bb$ final states, where $\ell = e,~\mu,~\mathrm{or}~\tau$, using $pp$ collision data at 13 TeV corresponding to an integrated luminosity of 139 fb$^{-1}$ collected by the ATLAS detector at the LHC. The search considers the one-lepton channel, where an electron or muon is successfully reconstructed, as well as the zero-lepton channel relying on missing transverse momentum when the electron or muon from the $W$-boson decay is not reconstructed, or when $\ell$ is a hadronically decaying $\tau$-lepton. The search is conducted by examining the reconstructed invariant or transverse mass distributions of $W^\prime \to WH$ candidates in the mass range from $400~\mathrm{GeV}$ to $5~\mathrm{TeV}$. No significant excess is observed and $95\%$ confidence level upper limits between 0.7~pb and 0.4~fb are placed on the production cross-section times branching fraction of $W^\prime$ bosons in heavy-vector-triplet models.