Photon pairs from relativistic heavy ion collisions and the quark hadron phase transition

A search for photon pairs produced from the annihilation of quarks and of pions in relativistic heavy ion collisions may provide confirmation of a quark hadron phase transition. If there is no phase transition, the resulting high temperatures could lead to a much larger production of large mass pairs from pion annihilation, and may even carry a clear signature of kaon annihilation.