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Description
The quark‑gluon plasma (QGP) produced in relativistic heavy‑ion collisions rapidly thermalizes and expands, yet its total entropy – a cornerstone thermodynamic quantity – remains inaccessible to direct experimental measurement from final‑state particles. In this work we uncover a fundamental scaling relation between the entropy of the QGP and the Kolmogorov complexity $\Xi$ of the final‑state particle pointcloud {ID,$p_i$}. From holographic perspective, the high-temperature quark-gluon plasma (QGP) can be analogized to a strongly coupled gauge field theory (for example, N=4 SYM), whose time evolution dynamics can be mapped to the formation and evolution of an AdS black hole. First, the logarithmic factor $-\ln\Xi$ in entropy relation naturally emerges from holographic complexity conjectures (Complexity = Volume/Action), reflecting critical‑point‑like scaling of the correlation length near thermalization. The power‑law prefactor $\Xi^{b}$ encodes the fractal dimension of the momentum‑space distribution, bridging the pattern complexity of the final state with the entanglement structure of the QGP. This relation establishes a direct link between the algorithmic information content of observed particles and the fundamental thermodynamic entropy of the strongly coupled system, offering a new probe of thermalization and possible critical behavior.
To enable this discovery, we design a PointNet++ regression model that predicts the total entropy directly from the particle point cloud (three‑momenta and species) of each event. Trained on a large dataset of A+A and p+A collisions. The model achieves high predictive accuracy $(R^{2}>0.97$) by combining learned hierarchical features with extracted global observables (elliptic flow $v_{2}$), $p_{T}$ kurtosis, sphericity) and local descriptors (density, diversity, anisotropy). Our work demonstrates that point‑cloud deep learning can extract thermodynamic information from unstructured particle data, opening a path toward entropy‑based diagnostics in high‑energy nuclear physics. Finally, we shall present reslults related to experiment measurement.
| 请选择分会 | 高能重离子物理 |
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