Speaker
Description
Quantifying the path-length and flavor dependence of parton energy loss is essential for converting jet quenching measurements into microscopic constraints on the transport properties of deconfined QCD matter. In our previous study~[1], using $R_{\mathrm{AA}}$ data for different hadron species within a fixed collision centrality, we simultaneously extracted the parton energy loss of gluons ($g$), light quarks ($q$), charm quarks ($c$) and bottom quarks ($b$). In the present study~[2], we further extend the parametric jet-quenching framework by incorporating a path-length exponent, enabling a calibration of how parton energy loss scales with the length of the traversed QCD medium. Combining next-to-leading-order perturbative QCD calculations of parton production, a updated ansatz for parton energy loss and parton fragmentation functions, we compute the $R_{AA}$ of charged hadrons, $D$ mesons, and $B$-decayed $J/\psi$. Through a Bayesian inference to the available experimental data in Pb+Pb collison across all centrality classes, we find that the average parton energy loss follows a path-length dependence of $\langle \Delta \mathrm{E} \rangle \propto L^{\kappa}$, with $\kappa = 1.6$ for diffrent parton flavors. Moreover, we identify strong posterior correlations among the overall energy-loss strength, transverse-momentum dependence, fluctuation parameter, and path-length dependence. Those provide a stringent test of perturbative QCD descriptions of in-medium parton shower evolution.
Reference:
[1] Wen-Jing Xing, Shanshan Cao, and Guang-You Qin, Phys.Lett.B 850 (2024) 138523.
[2] Jian-Yao He, Wen-Jing Xing, Xun Chen, Shanshan Cao, and Guang-You Qin, in preparation.
