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arXiv · 2411.13107

Constraining the Phase-Transition EoS using the Energy Dependence of Directed Flow

Zhi-Min Wu·Gao-Chan Yong·Qingfeng Li
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Abstract

We propose a hybrid equation of state (VDF+MIT EoS) to describe the hadron-quark phase transition in dense nuclear matter. By coupling this EoS with the AMPT-HC transport model and comparing to recent experimental data on proton and $\Lambda$ directed flow $v_1$, we constrain the transition to likely occur near $5\rho_0$--$6\rho_0$, ruling out transitions below $3\rho_0$. Furthermore, we introduce the energy derivative of the mid-rapidity $v_1$ slope, $d(dv_1/dy)/d(\sqrt{s_{NN}})$, as a weakly model-dependent observable. Its zero crossing provides a direct signature of the phase transition critical point, offering a new tool for mapping the QCD phase diagram in future experiments.

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Zhi-Min Wu, Gao-Chan Yong, Qingfeng Li. 2024-11-20. Constraining the Phase-Transition EoS using the Energy Dependence of Directed Flow. https://doi.org/10.1103/4dq8-g746

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