Study of the thermodynamic properties of hot QCD matter with the CMS experiment

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.

arXiv comment8 pages, 4 figures, Proceedings of Workshop of Advances in QCD at the LHC and the EIC