BAPO: Stabilizing Off-Policy Reinforcement Learning for LLMs via Balanced Policy Optimization with Adaptive Clipping. - Zhiheng Xi; Xin Guo; Yang Nan; Enyu Zhou; Junrui Shen; Wenxiang Chen; Jiaqi Liu; Jixuan Huang; Zhihao Zhang 002; Honglin Guo; Xun Deng; Zhikai Lei; et al. (CoRR, 2025)