Recent lattice studies of string breaking in QCD with dynamical quarks dete
rmine the in-medium temperature dependence of the heavy quark potential. Co
mparing this to the binding energies of different quarkonium states, we che
ck if these can decay into open charm/beauty in a confined hadronic medium.
Our studies indicate in particular that the chi (c) and the psi ' dissocia
te into open charm below the deconfinement point. (C) 2001 Published by Els
evier Science B.V.