Search for the elusive jet-induced diffusion wake in \(Z/\gamma\)-jets with 2D jet tomography in high-energy heavy-ion collisions

• Published in: arXiv.org
• Main Authors: Yang, Zhong, Chen, Wei, He, Yayun, Weiyao Ke, Pang, Longgang, Wang, Xin-Nian
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 19.03.2022
• Subjects: Correlation; Depletion; Diffusion effects; Gluons; Hadrons; Heavy ions; Ionic collisions; Large Hadron Collider; Partons; Subtraction; Tomography; Two dimensional jets
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2101.05422

Diffusion wake is an unambiguous part of the jet-induced medium response in high-energy heavy-ion collisions that leads to a depletion of soft hadrons in the opposite direction of the jet propagation. New experimental data on \(Z\)-hadron correlation in Pb+Pb collisions at the Large Hadron Collider show, however, an enhancement of soft hadrons in the direction of both the \(Z\) and the jet. Using a coupled linear Boltzmann transport and hydro model, we demonstrate that medium modification of partons from the initial multiple parton interaction (MPI) gives rise to a soft hadron enhancement that is uniform in azimuthal angle while jet-induced medium response and soft gluon radiation dominate the enhancement in the jet direction. After subtraction of the contributions from MPI with a mixed-event procedure, the diffusion wake becomes visible in the near-side \(Z\)-hadron correlation. We further employ the longitudinal and transverse gradient jet tomography for the first time to localize the initial jet production positions in \(Z/\gamma\)-jet events in which the effect of the diffusion wake is apparent in \(Z/\gamma\)-hadron correlation even without the subtraction of MPI.