Orateur
Description
One of the fundamental aspects of the formation and interaction of heavy quark bound states in the quark-gluon plasma is the amount of their suppression, expected to be stronger for quarkonia with smaller binding energies. Indeed, past results show a significant suppression of $\Upsilon\mathrm{(1S)}$ mesons in heavy ion collisions, with $\Upsilon\mathrm{(2S)}$ mesons being even more suppressed. However, for the $\Upsilon\mathrm{(3S)}$ meson, only upper limits have been reported so far. At the same time, features like polarization of quarkonia or feed-down contributions from excited states remain to be assessed. In this talk, we report the observation of the $\Upsilon\mathrm{(3S)}$ meson and a detailed study of the production of $\Upsilon$ mesons in lead-lead collisions recorded by CMS. For the first time, the nuclear modification factor has been extended to the strongly suppressed $\Upsilon\mathrm{(3S)}$ state. The results are compared with model calculations describing the dynamics of quarkonia in a hot environment, whereas future prospects are shown too.
