On the $x_F$ Distribution of $J/\psi$'s Produced in Heavy Ion Collisions
  Thermal production of $J/\psi$ in the quark gluon plasma is reconsidered. We show that if screening effects are not strong enough, the ``in-plasma born'' $J/\psi$'s would generate a peak in the Feynman momentum distribution at $x_F \simeq 0$. 
F.O. Dur\~aes, F.S. Navarra and M. Nielsen