Advancements in the ATLAS Fast Chain for HL-LHC: Towards Efficient MC Production

The ATLAS Fast Chain represents a significant advancement in streamlining Monte Carlo (MC) production efficiency, specifically for the High Luminosity Large Hadron Collider. This project aims to simplify the MC production chain by eliminating intermediate formats, optimizing CPU utilization, and employing fast simulation methods to reduce disk usage and accelerate the process. Fast Chain leverages AtlFast3 methodologies for efficient calorimeter shower simulation and employs Fast Track Simulation for charged particles in the Inner Detector. Reconstruction speed optimization focuses on Inner Detector track reconstruction. Strategies like dedicated reconstruction configurations and track overlay from pre-mixed pile-up datasets are being explored. These proceedings provide an overview of the project’s objectives, methodologies, and ongoing developments, showcasing its potential to revolutionize MC production within the ATLAS experiment.