We present results of a detailed analysis of experimental data on the nuclear modification factor $R_{ AA}$ and the flow coefficient $v_2$ for light hadrons from RHIC for $0.2$ TeV Au+Au collisions and from LHC for $2.76$ and $5.02$ TeV Pb+Pb, and $5.44$ TeV Xe+Xe collisions. We perform calculations within the light-cone path integral approach to induced gluon emission. We use running $\alpha_s$ which is frozen at low momenta at some value $\alpha_{ s}^{ fr}$. We find that the RHIC data support somewhat larger value of $\alpha_{ s}^{ fr}$. For the $\chi^2$ optimized values of $\alpha_{ s}^{ fr}$, the theoretical predictions are in reasonable agreement with data on $R_{ AA}$ and $v_2$. Calculations made for different formation times and life-times of the QGP show that jet quenching at the RHIC and LHC energies is only weakly sensitive to the initial and final stages of the QCD matter evolution.
Categories: hep-ph nucl-th