  The precise measurement of physics observables and the test of their
consistency within the standard model (SM) are an invaluable approach,
complemented by direct searches for new particles, to determine the existence
of physics beyond the standard model (BSM). Studies of massive electroweak
gauge bosons (W and Z bosons) are a promising target for indirect BSM searches,
since the interactions of photons and gluons are strongly constrained by the
unbroken gauge symmetries. They can be divided into two categories: (a) Fermion
scattering processes mediated by s- or t-channel W/Z bosons, also known as
electroweak precision measurements; and (b) multi-boson processes, which
include production of two or more vector bosons in fermion-antifermion
annihilation, as well as vector boson scattering (VBS) processes. The latter
categories can test modifications of gauge-boson self-interactions, and the
sensitivity is typically improved with increased collision energy.
  This report evaluates the achievable precision of a range of future
experiments, which depend on the statistics of the collected data sample, the
experimental and theoretical systematic uncertainties, and their correlations.
In addition it presents a combined interpretation of these results, together
with similar studies in the Higgs and top sector, in the Standard Model
effective field theory (SMEFT) framework. This framework provides a
model-independent prescription to put generic constraints on new physics and to
study and combine large sets of experimental observables, assuming that the new
physics scales are significantly higher than the EW scale.
