Design and development of the core software for STCF offline data processing

The Super Tau Charm Facility (STCF) is a proposed electron-positron collider working at √s = 2 ∼ 7 GeV, and the peak luminosity is designed to be above 0.5 × 1035 cm-2s-1. The huge amount of scientific data brings great challenges to the offline data processing software, including the Monte Carlo simulation, calibration, reconstruction as well as the data analysis. To facilitate efficient offline data processing, the offline software of Super Tau Charm Facility (OSCAR) is developed based on SNiPER, a lightweight framework designed for HEP experiments, as well as a few state-of-art software in the HEP community, such as podio and DD4hep. This paper describes the design and implementation of the core software of OSCAR, which provides the foundation for the development of complex algorithms to be applied on the large data sets produced by STCF, particularly the way to integrate the common HEP software toolkits, such as Geant4, DD4hep and podio, into SNiPER. The software framework also provides a potential solution for other lightweight HEP experiments as well.