quasibound states: J/ψ decay and -atomic evidences

We use an interaction based in a constituent quark model to study possible quasibound states. Within this model the antiprotonium energy shifts are studied as a signal of such states. The threshold enhancement of J/Ψ decay is also studied, including FSI effects. They can reproduce this enhancement an other threshold enhancements, ruling out their interpretation as signals of bound states.