Studies of Vector Boson Scattering with an Upgraded ATLAS Detector at a High-Luminosity LHC

The Phase 2 upgrade of the ATLAS detector greatly increases the sensitivity to an extended electroweak symmetry-breaking sector beyond the Standard Model Higgs mechanism. A common feature of such an extended sector is the enhancement of longitudinal vector boson scattering at high energy. Using simplified detector performance parameterizations, we present the expected gain in sensitivity if the ATLAS dataset were increased from 300 fb−1 to 1 ab−1 and 3 ab−1 at a center-of-mass energy of 14 TeV .