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arXiv · 2602.00537

Model Study of Eigen-Microstate Signatures of Criticality in Relativistic Heavy-Ion Collisions

Ranran Guo·Jin Wu·Mingmei Xu·Zhiming Li·Zhengning Yin·Yufu Lin·Lizhu Chen·Yanhua Zhang·Jinghua Fu·Xiaosong Chen·Yuanfang Wu
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Abstract

We present a comprehensive model study of the eigen-microstate approach (EMA) for identifying critical fluctuations in relativistic heavy-ion collisions. Using UrQMD and two stochastic baseline models, we demonstrate that EMA is insensitive to conventional short-range correlations and effectively filters out non-critical backgrounds. Critical fluctuations embedded via event-level or particle-level replacement with CMC events generate characteristic cluster-like eigen-microstate patterns and enhanced leading eigenvalues, with event-level criticality producing stronger responses. The eigen microstates exhibit the same pattern across different scales, demonstrating that the fractal nature of critical fluctuations is captured by the eigen microstates. Finite-size scaling of eigenvalue ratios exhibits fixed-point behavior, confirming the largest eigenvalue as an effective order-parameter-like quantity. These results demonstrate that EMA offers a robust and background-independent method for critical-point searches in the RHIC Beam Energy Scan and future heavy-ion experiments.

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Ranran Guo, Jin Wu, Mingmei Xu, Zhiming Li, Zhengning Yin, Yufu Lin, Lizhu Chen, Yanhua Zhang, Jinghua Fu, Xiaosong Chen, Yuanfang Wu. 2026-01-31. Model Study of Eigen-Microstate Signatures of Criticality in Relativistic Heavy-Ion Collisions. https://arxiv.org/abs/2602.00537

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