Speaker
Description
Jet quenching provides a valuable measure of the opacity of the quark-gluon plasma (QGP) produced in high-energy heavy-ion collisions. However, substantial suppression of charged hadron spectra is observed in highly peripheral collisions, despite the expectation of negligible jet-QGP interactions in this regime. In this work, we demonstrate that the suppression observed in highly peripheral collisions is predominantly driven by the dilute nucleon overlap in the initial state, rather than an onset of strong jet-QGP interactions. To quantitatively address this, we develop a HIJING-based initial condition model that accounts for the impact parameter dependence of both inelastic nucleon-nucleon (NN) collisions and the number of hard partonic scatterings per inelastic NN collision. This dependence introduces a geometric bias effect on the jet yield within a given centrality class of nucleus-nucleus (AA) collisions. Furthermore, we incorporate the Linear Boltzmann Transport (LBT) model to simulate jet-QGP interactions, introducing a large $p_{z}$-scheme for fake partons to eliminate unphysical enhancements of the hadron spectrum in peripheral AA collisions. By combining the geometric bias effect obtained from the HIJING-based model and the QGP effect simulated using the LBT model, we achieve a unified description of the charged hadron nuclear modification factor ($R_{AA}$) from central to highly peripheral Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV. Our findings highlight the crucial role of initial-state collision geometry in properly interpreting jet quenching observables in small collision systems.
| Academic Status | I am a Ph.D. student |
|---|
