Evidence for sequential Υ(nS) suppression in light ion collisions
Abstract
Bound states of heavy quark-antiquark pairs, known as quarkonia, have long been regarded as particularly sensitive probes of the quark-gluon plasma (QGP). Comparing quarkonium yields in collisions of heavy nuclei, such as gold or lead, with a proton-proton (pp) reference reveals a characteristic pattern of sequential suppression, in which weakly-bound excited states are more strongly suppressed than the ground states. We report the first measurements of the three lowest mass S-wave vector bottomonium resonances, the ground state Υ(1S) and the excited states Υ(2S) and Υ(3S), in oxygen-oxygen collisions at a center-of-mass energy per nucleon pair of √(sNN) = 5.36 TeV. Measurements of the yields of the Υ(1S) and Υ(2S) resonances in neon-neon collisions, at the same √(sNN), are also presented. The Υ(2S)/Υ(1S) ratio is found to be significantly below the measured pp reference value, and the Υ(3S)/Υ(1S) ratio shows an even larger reduction. The significance of the relative Υ(3S) to Υ(2S) suppression exceeds three standard deviations. These results provide evidence for the sequential suppression of Υ(nS) states in light ion collisions, similar to observations made in lead-lead and gold-gold collisions, generally attributed to the presence of a QGP medium.
Related
- System-size dependence of bottomonium suppression from Pb-Pb to light-ion collisions
- Sequential Clusterization of Light Nuclei and Hypernuclei in Heavy-Ion Collisions within a Wigner Function Coalescence Framework
- Color screening versus thermal decay as the mechanism of Υ suppression in high energy nuclear collisions
- Measurement of forward jet suppression in Pb+Pb collisions at √(sNN)=5.02$ TeV with the ATLAS detector
- Theoretical Review on Bulk Properties and Light/Strange Hadron Production in Heavy-Ion Collisions
BibTeX
@misc{collaboration2026evidence,
title = {{Evidence for sequential $Υ$(nS) suppression in light ion collisions}},
author = {CMS Collaboration},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2607.13758},
eprint = {2607.13758},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.13758},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Evidence for sequential Υ(nS) suppression in light ion collisions
AU - CMS Collaboration
PY - 2026
DA - 2026/09/22
PB - arXiv
DO - 10.48550/arxiv.2607.13758
UR - https://arxiv.org/abs/2607.13758
AB - Bound states of heavy quark-antiquark pairs, known as quarkonia, have long been regarded as particularly sensitive probes of the quark-gluon plasma (QGP). Comparing quarkonium yields in collisions of heavy nuclei, such as gold or lead, with a proton-proton (pp) reference reveals a characteristic pattern of sequential suppression, in which weakly-bound excited states are more strongly suppressed than the ground states. We report the first measurements of the three lowest mass S-wave vector bottomonium resonances, the ground state Υ(1S) and the excited states Υ(2S) and Υ(3S), in oxygen-oxygen collisions at a center-of-mass energy per nucleon pair of √(s_NN) = 5.36 TeV. Measurements of the yields of the Υ(1S) and Υ(2S) resonances in neon-neon collisions, at the same √(s_NN), are also presented. The Υ(2S)/Υ(1S) ratio is found to be significantly below the measured pp reference value, and the Υ(3S)/Υ(1S) ratio shows an even larger reduction. The significance of the relative Υ(3S) to Υ(2S) suppression exceeds three standard deviations. These results provide evidence for the sequential suppression of Υ(nS) states in light ion collisions, similar to observations made in lead-lead and gold-gold collisions, generally attributed to the presence of a QGP medium.
ER -