Giovanni Pelliccioli (Uni Milano Bicocca)

Electroweak-boson pairs at the LHC: a look from every angle

Accessing the spin correlations in multi-boson LHC processes represents an important step to better understand the eletroweak and scalar sector of the Standard Model (SM), to enhance the sensitivity to potential new-physics effects, and to evaluate observables sensitive to quantum entanglement at high energies. The spin correlations and polarisations can be extracted from LHC data as coefficients associated to the angular structure of the boson decay products. Focusing on electroweak-boson pair production in the fully leptonic decay channel, we show that higher-order corrections in the SM, off-shell modelling, fiducial selections and neutrino reconstruction are essential for a sound determination of angular coefficients, and consequently for their correct interpretation in terms of quantum observables.
Additionally, we examine how angular coefficients change owing to new-physics effects, expressed in terms of higher-order effective operators, with a stress on the impact of CP-even and CP-odd modifications of the SM triple-gauge coupling.