REFINE-DP: Diffusion Policy Fine-tuning for Humanoid Loco-manipulation via Reinforcement Learning. - Zhaoyuan Gu; Yipu Chen; Zimeng Chai; Alfred Cueva; Thong Nguyen; Yifan Wu; Huishu Xue; Minji Kim; Isaac Legene; Fukang Liu; Matthew Kim; Ayan Barula; et al. (CoRR, 2026)