Constraining the phase-transition equation of state using the energy dependence of directed flow
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 $Λ$ directed flow $v_1$, we constrain the transition to likely occur near $5ρ_0$--$6ρ_0$, ruling out transitions below $3ρ_0$. 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.
Fields of Study & Subjects
High-Energy Particle Collisions Research
Theoretical and Computational Physics
Quantum Chromodynamics and Particle Interactions
Publication details
- Journal / source
- Physical review. D/Physical review. D.
- Publisher
- American Physical Society (APS)
- Volume
- 113
- Issue
- 3
- Publication date
- 22 January 2026
- Language
- EN