English

Observation of the jet diffusion wake using dijets in heavy ion collisions

Nuclear Experiment 2026-03-03 v2 High Energy Physics - Experiment

Abstract

Energetic quarks and gluons traversing a hot and dense quark-gluon plasma deposit energy and momentum into the medium before hadronizing to collimated sprays of particles, known as jets. This energy-momentum deposition is expected to produce medium responses, collectively known as jet wakes, with ``diffusion wake'' denoting a depletion of particles in the direction opposite to the propagating jet. These phenomena are studied by comparing dijet-hadron correlations measured in lead-lead (PbPb) and proton-proton (pp) collisions to assess jet-induced modifications of bulk particle production. The analysis uses PbPb and pp data recorded at a nucleon-nucleon center-of-mass energy sNN\sqrt{s_\mathrm{NN}} = 5.02 TeV with the CMS detector at the CERN LHC. By exploring how the dijet-hadron correlation distributions differ for various pseudorapidity separations of the two jets in the dijet, the presence of a jet diffusion wake is firmly established. The wake has a significance greater than 5 standard deviations for charged particles in the transverse momentum range 1 <\lt pTp_\mathrm{T} <\lt 2 GeV. The measurements are compared with various model predictions with and without jet wake effects, providing new insights into quark-gluon plasma properties and the formation of jet-induced wakes.

Keywords

Cite

@article{arxiv.2602.19431,
  title  = {Observation of the jet diffusion wake using dijets in heavy ion collisions},
  author = {CMS Collaboration},
  journal= {arXiv preprint arXiv:2602.19431},
  year   = {2026}
}

Comments

Submitted to Physical Review Letters. All figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-25-012 (CMS Public Pages). This version corrects the CERN reference to CERN-EP-2026-017