Precision study at Z-pole at future colliders: the framework and the tool
Lisong Chen (KIT)

Future electron-positron colliders, such as the CEPC, FCCee, and ILC, are poised to explore a new precision frontier, enabling an unprecedented level of scrutiny of the electroweak (EW) sector of the Standard Model (SM) and potentially uncovering new physics beyond the SM. Achieving this requires a deeper understanding of the SM through the calculation of radiative corrections to various well-defined observables, specifically the electroweak precision observables (EWPOs).

The first part of the talk provides a brief review of the EWPOs and the forefront of precision studies of these observables at future electron-positron colliders. In the second part, we introduce a novel modular framework for describing EW scattering and decay processes, including but not limited to Z-resonance physics. This framework maintains gauge invariance while ensuring extensibility. It has been implemented in the publicly available object-oriented C++ library GRIFFIN, featuring full NNLO and leading higher-order contributions on the Z-resonance, as well as NLO corrections off resonance. This framework is also capable of making predictions for new physics models relevant to these processes and can interface with Monte Carlo programs to account for real radiation.