Quarkonium Suppression in pPb Collisions at CMS and Timing Detectors for Future Collider Experiment

Describing the strong interaction at low momentum transfers remains a central challenge in Quantum Chromodynamics, where perturbative methods fail and precise measurements are required. The study of heavy-ion collisions at the Large Hadron Collider has firmly established the existence of the quark–gluon plasma (QGP), yet recent experimental results suggest that QGP-like phenomena may also emerge in smaller systems such as pp and pPb collisions. Quarkonium, bound states of heavy quark–antiquark pairs, provide sensitive probes in this context because their survival strongly depends on binding energy and the surrounding medium. The excited-to-ground state charmonium cross-section ratio, 𝟁(2S)/J/𝟁, measured in pPb collisions at 8.16 TeV with the CMS detector, shows a statistically significant suppression of the prompt ratio with increasing multiplicity, representing the first such observation in proton–ion collisions. In addition, bottomonium production has been studied through 𝚼(nS)/𝚼(1S) yield ratios, which exhibit suppression patterns consistent with those of the charmonium results, indicating that a similar final-state effect may be at play. These results indicate final-state effects preferentially dissociate weakly bound states, consistent with co-mover interactions or, potentially, the formation of QGP. Together, these measurements provide additional constraints on hadronization models of heavy quarks in nuclear collisions. In parallel, recent detector R&D has explored AC–LGAD prototypes to address the demands of next-generation collider experiments, where dense environments require simultaneous spatial and temporal precision. Beam tests demonstrate timing resolutions of 20–35 ps and spatial resolutions of 12–20 µm, establishing AC–LGADs as promising candidates for 4D tracking layers in future experiments, including the future Electron–Ion Collider.

Author dc:creator

• Shirsendu Nanda (17496609)

• Quarkonium (charmonium and bottomonium) suppression in pPb collisions at CMS + timing detectors based on AC-LGAD for future collider experiments such as EIC

Statement dc:rights

• In Copyright
• Open Access after 2028-01-01

DOI dc:identifier

https://doi.org/10.25417/uic.31451719.v1

OAI identifier oai:identifier

oai:figshare.com:article/31451719