Hadronisation of in-medium $c\bar c$ pairs to the exotic $X(3872)$

Abstract

The separation of $c\bar c$ quarks in the quark-gluon plasma and the characteristic size of the final state quarkonia should lead to the observed hadron ratios in nuclear collisions. Such dependence manifests itself through the Fermi Golden rule, where hadron ratios are sensitive to the inner product between in-vacuum and in-medium wave functions. A novel hard probe is the exotic $X(3872)$, which is expected to have a molecular and a compact component. We bridge more than a decade of several LHC experimental results on hard probes, namely $J/Ψ$, $Ψ(2S)$ and $X(3872)$ hadrons, to the degree of separation and dissociation of in-medium hidden-charm systems.