  Measurements of vector boson polarisation in vector boson production
processes offer a powerful probe of the electroweak symmetry breaking
mechanism, scrutinising the Standard Model and new physics scenarios alike.
Since massive vector bosons can only be observed as intermediate particles,
polarised cross section templates from simulation are necessary to extract
their polarisation from measurable unpolarised distributions. In this work we
present an extension of the SHERPA Monte-Carlo event generator allowing the
simulation of polarised cross sections for vector boson production processes.
Based on the narrow-width approximation, polarised cross sections of all
possible polarisation combinations for an arbitrary number of intermediate
vector bosons can be simulated in a single simulation run. In addition, it is
possible to directly predict the interference between different intermediate
polarisation states, and various differing polarisation definitions can be
studied simultaneously. Besides the simulation of polarised cross sections at
fixed LO and LO+PS accuracy as well as in multijet merged calculations, we also
present parton-shower-matched polarised cross sections with approximate NLO QCD
corrections in the vector boson production processes. We demonstrate that the
differences of this approximation to full NLO QCD predictions are small and it
thus opens up the possibility for fully-simulated calculations at the hadron
level including polarisation information and higher-order QCD effects for the
first time.
