Liu, Y. et al. 2026. OPERA: A Reinforcement Learning--Enhanced Orchestrated Planner-Executor Architecture for Reasoning-Oriented Multi-Hop Retrieval. Proceedings of the AAAI Conference on Artificial Intelligence. 40, 38 (Mar. 2026), 32258–32266. DOI:https://doi.org/10.1609/aaai.v40i38.40499.