Software Validation Infrastructure for the ATLAS High-Level Trigger

The ATLAS trigger will need to achieve a 10−7 rejection factor against proton-proton collisions, and still be able to efficiently select interesting events. After a first hardware-implemented processing level, the final event selection is done by the high-level trigger (HLT), implemented on software. With more than 100 contributors and around 250 different packages, a thorough validation of the HLT software is essential. This paper describes the existing infrastructure used for validating the HLT software.