About 40-50 % of the quarkonium ground states J/psi(1S) and Upsilon(1S)
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 CDF data on bottomonium
production, we then obtain first predictions for sequential Upsilon suppression
in nuclear collisions.Comment: 19 pages, LaTeX, 11 figure