中国物理学会高能物理分会第十三届全国粒子物理学术会议（2021）

The measurement of azimuthal correlations between two particles is a powerful tool to investigate the properties of strongly-interacting nuclear matter created in ultra-relativistic heavy-ion collisions. in particular, studying the near-side and away-side hadron yields associated with trigger particles can provide important information to understand both the jet-medium interaction and hadron production mechanism. We study two-particle correlations with $\mathrm{V^{0}}$( $\mathrm{K^{0}_{s}}$,$\Lambda/\overline{\Lambda}$) and charge hadrons as trigger particles of transverse momentum $8 < p_\mathrm{T,trig} < 16 \mathrm{GeV}/c$,and associated charged particles of $1 \mathrm{GeV}/c< p_\mathrm{T,assoc} < p_\mathrm{T,trig}$ at mid-rapidity in pp and Pb–Pb collisions at a center-of-mass energy of $5.02$ TeV per nucleon pair. After subtracting the contributions of the flow background $v_{2}$ and $v_{3}$ , the per-trigger yields are extracted for two-particle azimuthal differences$|\Delta\varphi|<0.9$ on the near-side and $|\Delta\varphi-\pi|<1.2$ on the away-side. The ratio of the per-trigger yields in Pb–Pb collisions with respect to pp collisions , $I_\mathrm{AA}$ , is measured in the near-side and away-side in the most central $0-10\%$ collisions.On the near-side, a significant enhancement of $I_\mathrm{AA}$ from 1.5 to 2 for different particles species is observed at the lowest $p_\mathrm{T,assoc}$. On the away-side, suppression to the level of ($I_\mathrm{AA}$ $\approx 0.6$ ) for $p_\mathrm{T,assoc}>3 \mathrm{GeV}/c$ is observed as expected from strong in-medium energy loss while an enhancement reaching 2 at lowest $p_\mathrm{T,assoc}$ . The data are compared to AMPT, HIJING and EPOS models. Most calculations qualitatively describe the near-side and away-side yield modification at intermediate and high $p_\mathrm{T,assoc}$.