I'm having a problem understanding QGP. Hadrons are bound states of quarks which interact by interchanging colour. Now, as I understood we haven't observed free quarks because the force rises by distance and that force is really strong. As I read in QGP quarks and gluons are not bound, you can't tell the difference between nuclei. But how come you can't observe a free quark? For example, what stops quarks just from flying away from that plasma? Why when you cool things down you don't get some pentha quarks states, since it was all mixed up?