Heavy Flavor Measurements in Heavy Ion Collisions by PHENIX at RHIC

Studying J/psi production in Au+Au collisions provides insight into the color screening length of the QGP medium produced in heavy ion collisions. However, recent measurements in d+Au collisions show that cold nuclear matter effects are large, and understanding them is critical to the interpretation of the heavy ion data. We find that the new d + Au data requires a nuclear modification which is stronger than linearly or exponentially dependent on the nuclear thickness at forward rapidity. Extrapolating the cold nuclear matter effects to Au+Au collisions we find that, at midrapidity, there is suppression beyond cold nuclear matter effects, and that a similar statement at forward rapidity must wait for a full description of the d + Au data.