We present the first public implementation of antenna-based QCD initial- and final-state showers. The shower kernels are antenna functions, which capture not only the collinear dynamics but also the leading soft (coherent) singularities of QCD matrix elements. We define the evolution measure to be inversely proportional to the leading poles, hence gluon emissions are evolved in a measure inversely proportional to the eikonal, while processes that only contain a single pole (e.g., ) are evolved in virtuality. Non-ordered emissions are allowed, suppressed by an additional power of . Recoils and kinematics are governed by exact on-shell phase-space factorisations. This first implementation is limited to massless QCD partons and colourless resonances. Tree-level matrix-element corrections are included for QCD up to (4 jets), and for Drell–Yan and Higgs production up to (V / H + 3 jets). The resulting algorithm has been made publicly available in Vincia  2.0.

-We present a complete formalism for final-state (timelike) dipole-antenna showers including fermion masses, but neglecting polarization and finite-width effects. We make several comparisons of tree-level expansions of this shower algorithm to fixed-order matrix elements for hadronic Z decays, up to and including Z → 6 partons, to which the algorithm can be consistently matched over all of phase space. We also compare to analytical resummations at the NLL level. The shower algorithm has been implemented in the publicly available VINCIA plugin to the PYTHIA 8 event generator, which enables us to compare to experimental data at the fully hadronized level. We therefore also include comparisons to selected observables in b-tagged Z decays.