Polarised weak-bosons pairs at the LHC: a view on the electroweak sector from every angle, G. PELLICCIOLI (Uni Milano-Bicocca) – September 19th 2025 @2pm

Probing the polarisation of weak bosons represents a crucial step to answer a key question of particle physics: how is the electroweak symmetry broken in nature?

Owing to the tight connection between the scalar-sector realisation and the longitudinal mode of massive gauge bosons, accessing the polarisation of W and Z bosons allows to investigate more in depth the Standard Model (SM) dynamics and enhances the sensitivity to potential new-physics effects.

Therefore, precise and accurate predictions in and beyond the SM are needed for the production and decay of polarised bosons in LHC processes, in order to perform improved template fits of the experimental LHC data.

We have proposed a general strategy to calculate polarised cross-sections including radiative QCD and electroweak (EW) corrections to the production and decay of W and Z bosons. This method has been successfully applied up to NNLO QCD + NLO EW accuracy in di-boson inclusive production, and up to NLO QCD + NLO EW in vector-boson scattering. The matching of fixed-order calculations to parton shower (PS), representing a necessary building block for a more accurate and realistic interpretation of the data, has also been achieved at NLO QCD accuracy.

After covering general aspects, we will present a selection of recent phenomenological results relevant for LHC polarisation analyses, including precise SM predictions for ZZ inclusive production [1] and WZ scattering [2], as well as beyond-the-SM predictions in the SMEFT framework for WZ inclusive production [3].

[1] Carrivale, Pelliccioli et al. arXiv:2505.09686
[2] Denner, Haitz, Lombardi, Pelliccioli and Franken, to appear
[3] Haisch, Linder, Pelliccioli, Re and Zanderighi, arXiv:2507.21768 

The seminar will be in English.