| CMS Note | |
| Report number | CMS-CR-2026-023 |
| Title | Study of the thermodynamic properties of hot QCD matter in the CMS experiment |
| Author(s) | Bernardes, Cesar Augusto (SAO_PAULO) |
| Publication | 2026 |
| Collaboration | CMS Collaboration |
| Imprint | 20 Mar 2026 |
| Number of pages | 9 |
| Presented at | Advances in QCD at the LHC and the EIC, Rio De Janeiro, Br, 10 - 13 Nov 2025 |
| Subject category | Detectors and Experimental Techniques |
| Accelerator/Facility, Experiment | CERN LHC ; CMS |
| Keywords | HeavyIons |
| Abstract | These proceedings summarize recent CMS measurements at the LHC that extract the squared speed of sound, \(c_s^2\), of strongly interacting matter at extreme temperatures from the multiplicity dependence of the mean transverse momentum in ultra-central lead-lead (PbPb) collisions at \(\sqrt{s_{\mathrm{NN}}} = 5.02\ \mathrm{TeV}\). The analysis yields \(c_s^2 = 0.241 \pm 0.002\, (\mathrm{stat}) \pm 0.016\, (\mathrm{syst})\) at an effective temperature of \(T_{\mathrm{eff}} = 219 \pm 8\, (\mathrm{syst})\ \mathrm{MeV}\), in good agreement with lattice-QCD calculations. Complementary studies in proton-lead (pPb) collisions are also presented to investigate possible quark-gluon plasma signatures in smaller systems. |
Record created 2026-05-20, last modified 2026-05-20
