Revisiting identified-particle $p_{\mathrm{T}}$ spectra using the Boltzmann–Gibbs blast-wave model in a Bayesian inference framework

摘要: We perform a Bayesian analysis of transverse momentum ($p_{\mathrm{T}}$) spectra of identified particles, i.e., pions, kaons, and protons, at midrapidity in Au+Au collisions and Pb+Pb collisions using the Boltzmann–Gibbs blast-wave (BGBW) model. We investigate whether it is possible to simultaneously describe the $p_{\mathrm{T}}$ spectra of identified particles without imposing the particle species-dependent $p_{\mathrm{T}}$ fit ranges -- a practice that was followed in conventional blast-wave model studies to achieve reasonable simultaneous fits. Using Bayesian analysis, our results indicate that the BGBW model can provide a reasonable simultaneous description of the \(p_{\mathrm{T}}\) spectra of pions, kaons, and protons over extended fit ranges, reaching the available data (\(\sim2\) GeV/\(c\)) in Au+Au collisions and 3 GeV/\(c\) (the \(p_{\mathrm{T}}\) upper limit adopted in conventional blast-wave model studies) in Pb+Pb collisions. The extracted parameters remain broadly consistent with those obtained from conventional BGBW simultaneous fits, while the extension of the fit range leads to moderate changes in some parameters. Furthermore, Bayesian analysis yields well-constrained posterior distributions for the kinetic freeze-out temperature $T_{kin}$, the average transverse flow velocity $\langle \beta_{\mathrm{T}}\rangle$, and the exponent of the velocity profile $n$ and shows their correlations transparently. We suggest that the BGBW model in a Bayesian inference framework proposed can be applied in future data analyses to simultaneously describe the $p_{\mathrm{T}}$ spectra of identified particles and extract the relevant information about the collision system.