HE-LHC prospects for diboson resonance searches and electroweak WW/WZ production via vector boson scattering in the semi-leptonic final states

Abstract

This note presents the prospects of searches for new heavy resonances decaying to diboson (WW) and measurements of electroweak WW/WZ production via vector boson scattering (VBS) in association with a high-mass dijet system in the $\ell \hat{I}½qq$ final states ($W\to \ell \hat{I}½$, $W/Z\to qq$). The prospects are presented for an integrated luminosity of 15 ab${}^{-1}$ of proton-proton ($pp$) collisions at $\sqrt{s}=27$ TeV with an ATLAS-like detector simulated in the Delphes framework. The cross-section measurement of the electroweak $WW/WZ$ production in VBS processes is expected to reach the precision of $\sim$2-3\%, improving the expected accuracy at the HL-LHC by a factor of 2. Prospects are presented also for the separation of the longitudinal component of the electroweak $WW/WZ$ production, showing the expected significance of $\sim 3\ddot{I}ƒ$ is reached with 3 ab${}^{-1}$ for the single $\ell \hat{I}½qq$ channel and $\sim 5\ddot{I}ƒ$ for all the semi-leptonic channels combined. The diboson resonance searches are interpreted for sensitivity to a simplified phenomenological model with a heavy gauge boson. With 15 ab${}^{-1}$ of $pp$ data, the discovery reach for the new resonance is extended to 8 TeV.