Speaker
Description
Energy-energy correlator (EEC) is an excellent jet substructure observable owning to its strong sensitivity to jet physics at different scales. Using a hybrid Pythia 8 + LBT framework, we perform a complete realistic simulation on medium modification of heavy and light flavor jet EEC in heavy-ion collisions. A clear flavor hierarchy is observed for jet EEC in both vacuum and QGP due to the mass effect~[1]. Recently, both CMS and ALICE collaborations have observed a significant nuclear modification of jet EECs in heavy-ion collision relative to pp colisions. To interpret those measurements, we refine the modular description of jet production and evolution inside the quark-gluon plasma by matching vacumm parton shower to in-medium parton transport at a medium scale of $Q_{\mathrm{M}}$ = 2 GeV. Within this updated framework, we present numerical results for PbPb to pp ratios of energy-energy correlators inside jets for different cone size and transverse momentum intervals, which provide a good description of experimental data from both CMS and ALICE collaboration~[2]. Our study indicates that the small-angle enhancement is mainly driven by jet selection bias, the intermediate-angle suppression by parton energy loss, and the large-angle enhancement by medium-induced radiation and medium response. We further predict PbPb to pp ratios for $D$-tagged jets and $B$-tagged jets, finding that both medium suppression and enhancement becomes weaker due to the mass effect on jet-medium interactions. These results confirm jet EECs as a differential probe of jet modification in the QGP.
References:
[1] Wen-Jing Xing, Shanshan Cao, Guang-You Qin, and Xin-Nian Wang, Phys.Rev.Lett. 134 (2025) 5, 052301
[2] Wen-Jing Xing, Shanshan Cao, Guang-You Qin, and Xin-Nian Wang, in preparation.
