Study of the EEC discrimination power on quark and gluon jet quenching effects in heavy-ion collisions at $\sqrt{s}=5.02$ TeV

Abstract

We present a systematic investigation of flavor-dependent jet quenching using energy-energy correlators (EEC) in $\sqrt{\rm s}=5.02$ TeV Pb+Pb collisions. Employing the improved SHELL model, which incorporates collisional and radiative energy loss, as well as medium response, we quantify distinct quenching signatures for quark and gluon jets. Key findings include: (1) Pure quark jets exhibit strong EEC enhancement at large angular scales, while gluon jets show a bimodal enhancement pattern at both small and large scales; (2) Dual-shift decomposition in the EEC ratio reveals shifts toward large primarily driven by energy loss, while small-$R_{L}$~shifts extend beyond selection bias and indicate intrinsic enhancement of the gluon-initiated jets; (3) Quark jets experience global suppression of averaged energy weight $\langle\mathrm{weight}\rangle(R_{L})$, whereas gluon jets exhibit concentration toward small $R_{L}$; (4) Mechanism decomposition identifies elastic energy loss concentrating $\langle\mathrm{weight}\rangle(R_{L})$ toward small $R_{L}$, radiative loss dominating quark jet modification, and medium response amplifying large $R_{L}$ ~enhancement via soft hadrons. The observed flavor dependence in EEC modifications is dominantly driven by intrinsic jet structure differences rather than medium-induced mechanisms. We propose photon-tagged jets as quark proxies and inclusive charged-hadron jets as gluon proxies, finding they reproduce the respective flavor-specific quenching patterns. Our work establishes the EEC as a precision probe of color-charge-dependent jet-medium interactions, providing new constraints for the detailed $\hat{q}$ extraction and QGP tomography, while highlighting the critical role of pre-quenching flavor asymmetries.