RDataFrame enhancements for HEP analyses

In recent years, RDataFrame, ROOT’s high-level interface for data analysis and processing, has seen widespread adoption on the part of HEP physicists. Much of this success is due to RDataFrame’s ergonomic programming model that enables the implementation of common analysis tasks more easily than previous APIs, without compromising on application performance. Nonetheless, RDataFrame’s interfaces have been further improved by the recent addition of several major HEP-oriented features: in this contribution we will introduce for instance a dedicated syntax to define systematic variations, per-data-sample call-backs useful to define quantities that vary on a per-sample basis, simplifications of collection operations and the injection of just-in-time-compiled Python functions in the optimized C++ event loop.