Dk. Srivastava et al., PHOTON PAIRS FROM RELATIVISTIC HEAVY-ION COLLISIONS AND THE QUARK-HADRON PHASE-TRANSITION, Physics letters. Section B, 387(1), 1996, pp. 21-25
A search for photon pairs produced from the annihilation of quarks and
of pions in relativistic heavy ion collisions may provide confirmatio
n of a quark hadron phase transition. If there is no phase transition,
the resulting high temperatures could lead to a much larger productio
n of large mass pairs from pion annihilation, and may even carry a cle
ar signature of kaon annihilation.