11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

Two-particle azimuthal correlations are a powerful tool to investigate the details of the mechanisms of jet quenching and hadron production. Suitable candidates for these studies are strange mesons (${\mathrm{K}}_{\mathrm{S}}^0$) and baryons ($\mathrm{\Lambda }/\bar{\mathrm{\Lambda }}$), as their relative production rates differ for jets originating from quark or gluon. Measurements of near- and away-side hadron yields associated with these hadrons as trigger particles therefore provide additional constraining power for in-medium energy loss of different high-$p_{\mathrm{T}}$ partons and their fragmentation properties.

In this contribution, we present ratios of per-trigger yields in Pb-Pb collisions with respect to pp collisions, $I_{\mathrm{AA}}$ measured at midrapidity in the most central 0-10% collisions with the ALICE detector, with ${\mathrm{K}}_{\mathrm{S}}^0$, $\mathrm{\Lambda }/\bar{\mathrm{\Lambda }}$ and charged hadrons as trigger particles. A significant enhancement of $I_{\mathrm{AA}}$ for various particle species is found at the lowest associated-particle $p_{\mathrm{T},\mathrm{assoc}}$ on both the near- and away-side, while a strong suppression of $I_{\mathrm{AA}}$ for $p_{\mathrm{T},\mathrm{assoc}}$ $>3$ $\mathrm{GeV}/c$ on away-side is observed, as expected from strong in-medium energy loss. The data are compared to HIJING, AMPT and EPOS models, where the latter two qualitatively describe the near- and away-side yield modifications at intermediate and high $p_{\mathrm{T},\mathrm{assoc}}$.