  Longitudinal polarisation of the weak bosons is a direct consequence of
Electroweak symmetry breaking mechanism providing an insight into its nature,
and is instrumental in searches for physics beyond the Standard Model. We
perform a polarisation study of the diboson production in the $p p \to
e^+\nu_e\mu^-\bar\nu_\mu$ process at NNLO QCD in the fiducial setup inspired by
experimental measurements at ATLAS. This is the first polarisation study at
NNLO. We employ the double pole approximation framework for the polarised
calculation, and investigate NNLO effects arising in differential
distributions.
