Integration of Combine with FCCAnalyses

The Future Circular Collider (FCC) is a flagship proposal for a next-generation post-LHC particle accelerator to be built at CERN. As the FCC project scales up its physics performance studies, automating its software infrastructure to handle complex, large-scale data is critical. FCCAnalyses is the primary framework for these FCC studies, processing physics events in EDM4hep format into ROOT histograms. To extract physical meaning from these histograms - such as calculating upper limits, discovery significances, and cross-section measurements - physicists must employ dedicated statistical tools. Currently, this requires a manual translation of the data into Combine, a popular HEP statistical framework originating in the CMS Collaboration that is built on ROOT’s RooFit and RooStats libraries. This project will package Combine inside the Key4hep software stack and build a native Python interface within FCCAnalyses that automatically generates the necessary inputs to Combine, enabling a seamless end-to-end workflow. Crucially, the interface will be designed with a modular architecture, ensuring that other statistical frameworks can be seamlessly attached in the future.