AceReason-Nemotron: Advancing Math and Code Reasoning through
  Reinforcement Learning
Authors: name: Yang Chen, name: Zhuolin Yang, name: Zihan Liu, name: Chankyu Lee, name: Peng Xu, name: Mohammad Shoeybi, name: Bryan Catanzaro, name: Wei Ping

Despite recent progress in large-scale reinforcement learning (RL) for
reasoning, the training recipe for building high-performing reasoning models
remains elusive. Key implementation details of frontier models, such as
DeepSeek-R1, including data curation strategies and RL training recipe, are
often omitted. Moreover, recent research indicates distillation remains more
effective than RL for smaller models. In this work, we demonstrate that
large-scale RL can significantly enhance the reasoning capabilities of strong,
small- and mid-sized models, achieving results that surpass those of
state-of-the-art distillation-based models. We systematically study the RL
training process through extensive ablations and propose a simple yet effective
approach: first training on math-only prompts, then on code-only prompts.
Notably, we find that math-only RL not only significantly enhances the
performance of strong distilled models on math benchmarks (e.g., +14.6% /
+17.2% on AIME 2025 for the 7B / 14B models), but also code reasoning tasks
(e.g., +6.8% / +5.8% on LiveCodeBench for the 7B / 14B models). In addition,
extended code-only RL iterations further improve performance on code benchmarks
with minimal or no degradation in math results. We develop a robust data
curation pipeline to collect challenging prompts with high-quality, verifiable
answers and test cases to enable verification-based RL across both domains.
Finally, we identify key experimental insights, including curriculum learning
with progressively increasing response lengths and the stabilizing effect of
on-policy parameter updates. We find that RL not only elicits the foundational
reasoning capabilities acquired during pretraining and supervised fine-tuning
(e.g., distillation), but also pushes the limits of the model's reasoning
ability, enabling it to solve problems that were previously unsolvable.