Probing the Space-Time evolution of Heavy Ion Collisions with Bremsstrahlung

We examine the bremsstrahlung photons emitted in the central collisions of two gold nuclei at the Relativistic Heavy Ion Collider. While the measurements of the final hadrons can reveal only the amount of stopping, they tell us very little about the space-time evolution of the bulk matter in the collisions. By using two extreme collision scenarios, we argue that the low and medium energy bremsstrahlung photons can, not only reveal the amount of stopping, but also the finer details of the space-time evolution of the charges.