Update README.md

README.md

@@ -19,4 +19,4 @@ DeepRetrieval is a novel approach that uses reinforcement learning (RL) to train
 
 Please view our [GitHub page](https://github.com/pat-jj/DeepRetrieval) for instructions.
 
-[DeepRetrieval Paper](arxiv.org/abs/2503.00223)
+[DeepRetrieval Paper](https://arxiv.org/pdf/2503.00223)