In-medium modification of dijets in PbPb collisions at \(\sqrt{s_{\mathrm{NN}}} = 5.02 \) TeV

Modifications to the distribution of charged particles with respect to high transverse momentum \((p_{\mathrm{T}})\) jets passing through a quark-gluon plasma are explored using the CMS detector. Back-to-back dijets are analyzed in lead-lead and proton-proton collisions at \(\sqrt{s_{\mathrm{NN}}}= 5.02)) TeV via correlations of charged particles in bins of relative pseudorapidity and angular distance from the leading and subleading jet axes. In comparing the lead-lead and proton-proton collision results, modifications to the charged-particle relative distance distribution and to the momentum distributions around the jet axis are found to depend on the dijet momentum balance \(x_{j}\), which is the ratio between the subleading and leading jet \(p_{\mathrm{T}}\). For events with \(x_{j} \approx 1\), these modifications are observed for both the leading and subleading jets. However, while subleading jets show significant modifications for events with a larger dijet momentum imbalance, much smaller modifications are found for the leading jets in these events.

Reference: CMS Collaboration, "In-medium modification of dijets in PbPb collisions at \(\sqrt{s_{\mathrm{NN}}} = \) 5.02 TeV", JHEP 05 (2021) 116 [2101.04720]