Probing the charm-quark dead cone effect in heavy ion collisions
Abstract
The first experimental study of the dead-cone effect for the charm quark in heavy ion collisions is presented. The analysis is based on a sample of lead-lead (PbPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV, recorded by the CMS experiment at the CERN LHC in 2018 and corresponding to an integrated luminosity of 1.7 nb−1. The studied observable is the angular distribution of hard, collinear intrajet emissions that are selected with the late-kT grooming algorithm. The analysis is performed using inclusive jets and a sample of jets containing prompt D0 mesons. The angular distribution of late-kT emissions in PbPb collisions is found to be shifted towards larger angles in D0 jets relative to inclusive jets, indicating a suppression of collinear splittings for D0 jets. This shift, which is expected from the dead-cone effect, is consistent with a similar observation made in proton-proton collisions. The new measurement disfavors hypotheses that predict a filling of the charm-quark dead cone by medium-induced radiation in heavy ion collisions.
Related
- Charm quark production in heavy-ion collisions as a signature of pre-equilibrium
- The dead-cone effect in charm, bottom and top quark jets in angular and momentum space
- Evidence for the dead-cone effect in bottom quark initiated jets produced in proton-proton collisions at √s = 13 TeV
- The role of strangeness and baryon enhancement in heavy-quark hadronisation from pp to Pb−Pb collisions with ALICE
- Search for heavy neutral leptons in top quark decays with same-sign, same-flavor dilepton final states in proton-proton collisions at √s = 13 TeV
BibTeX
@misc{collaboration2026probing,
title = {{Probing the charm-quark dead cone effect in heavy ion collisions}},
author = {CMS Collaboration},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.01285},
eprint = {2611.01285},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.01285},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Probing the charm-quark dead cone effect in heavy ion collisions
AU - CMS Collaboration
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.01285
UR - https://arxiv.org/abs/2611.01285
AB - The first experimental study of the dead-cone effect for the charm quark in heavy ion collisions is presented. The analysis is based on a sample of lead-lead (PbPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV, recorded by the CMS experiment at the CERN LHC in 2018 and corresponding to an integrated luminosity of 1.7 nb^−1. The studied observable is the angular distribution of hard, collinear intrajet emissions that are selected with the late-k_T grooming algorithm. The analysis is performed using inclusive jets and a sample of jets containing prompt D^0 mesons. The angular distribution of late-k_T emissions in PbPb collisions is found to be shifted towards larger angles in D^0 jets relative to inclusive jets, indicating a suppression of collinear splittings for D^0 jets. This shift, which is expected from the dead-cone effect, is consistent with a similar observation made in proton-proton collisions. The new measurement disfavors hypotheses that predict a filling of the charm-quark dead cone by medium-induced radiation in heavy ion collisions.
ER -