Add link to paper

README.md

@@ -16,7 +16,7 @@ Github: https://github.com/hpcaitech/Open-Sora
 
 ## 🔆 Reports
 
-- **[Tech Report of Open-Sora 2.0](https://github.com/hpcaitech/Open-Sora-Demo/blob/main/paper/Open_Sora_2_tech_report.pdf)**
+- **[Tech Report of Open-Sora 2.0](https://huggingface.co/papers/2503.09642)**
 - **[Step by step to train or finetune your own model](docs/train.md)**
 - **[Step by step to train and evaluate an video autoencoder](docs/ae.md)**
 - **[Visit the high compression video autoencoder](docs/hcae.md)**