Comment on arXiv:2604.27678

Abstract

Shuang-Jie Liu et al. (arXiv:2604.27678) reported that the momentum-dependent nuclear mean field (MDI) with $K_0 = 230$ MeV &#39;can fit fairly&#39; the experimental data for Au + Au collisions at $\sqrt{s_{NN}} = 3$ GeV, whereas the momentum-independent nuclear mean fields (MID) with $K_0 = 230$ MeV and $K_0 = 380$ MeV &#39;can only partially describe&#39; the experimental results. We quantify these statements by performing $χ^2$ goodness-of-fit tests for the comparison between the theoretical calculations and the experimental distributions presented in that work. For the complete set of data, all three calculations show highly statistically significant disagreement with the experimental data, with (p-value) p < 0.001. For the $0-10\%$ centrality class, however, the MDI calculation with $K_0 = 230$ MeV gives p = 0.49, indicating no statistically significant disagreement with the experimental data for the proton transverse-momentum distributions and the rapidity dependence of the mean transverse momentum, whereas both MID calculations give p < 0.001. For the $10-40\%$ centrality class, the analysis of the directed flows of protons, $K^+$ mesons, and $Λ$-hyperons gives the largest p-values for MDI with $K_0 = 230$ MeV and MID with $K_0 = 380$ MeV, with p = 1.00 and p = 0.97, respectively. In contrast, the analysis of the corresponding elliptic flow data gives p < 0.001 for all three calculations. Our results demonstrate that the qualitative statements &#39;fit fairly&#39; and &#39;only partially describe&#39; depend substantially on the particular observables and centrality classes considered and cannot by themselves establish statistically acceptable agreement between the calculations and the experimental data.