Probing deconfinement across collision systems with Υ mesons in CMS

The hierarchy of bottomonium binding energies provides a state-resolved probe of deconfined QCD matter. This contribution presents the first CMS measurements of the three lowest Υ states in oxygen-oxygen collisions and of the two lowest states in neon-neon collisions at a center-of-mass energy per nucleon pair s NN = 5.36 TeV . A proton-proton sample at the same energy supplies the reference. Higher-to-lower-state yield ratios in the ion data are divided by their proton-proton counterparts, reducing shared experimental uncertainties and initial-state effects. The excited states are significantly depleted in both light ion systems. In oxygen-oxygen data, the relative suppression of Υ(3S) with respect to Υ(2S) reaches 3.2 standard deviations. The measurements span collision system, event activity, and transverse momentum and extend the established sequential pattern into a previously unexplored regime of symmetric nuclear collisions.