Quarkonium feed-down and sequential suppression

About 40–50 % of the quarkonium ground states $J/\psi \mathrm{}\left(1S\right)\mathrm{}$ and ${\rm Y}\mathrm{}\left(1S\right)\mathrm{}$ produced in hadronic collisions originate from the decay of higher excitations. In a hot medium, these higher states are dissociated at lower temperatures than the more tightly bound ground states, leading to a sequential suppression pattern. Using new finite temperature lattice results, we specify the in-medium potential between heavy quarks and determine the dissociation points of different quarkonium states. On the basis of recent Collider Detector at Fermilab (CDF) data on bottomonium production, we then obtain first predictions for sequential ${\rm Y}$ suppression in nuclear collisions.