M. Hentschel et al., DIPHOTON RATES FROM THERMALIZED MATTER RESULTING IN ULTRA-RELATIVISTIC HEAVY-ION COLLISIONS, Zeitschrift fur Physik. C, Particles and fields, 75(2), 1997, pp. 333-339
Diphoton radiation off strongly interacting matter resulting from ultr
arelativistic heavy-ion collisions is estimated for SPS and RHIC condi
tions. At SPS energies the thermal diphoton signal competes strongly w
ith the Drell - Yan like background, For RHIC energies we find that ra
diation from initially undersaturated (but gluon-rich) deconfined matt
er overwhelms the hadron gas at invariant mass M > 1 GeV; the Drell -
Yan like diphotons dominate at M > 2.5 GeV. Due to this the so-called
M-perpendicular to scaling is approximately obtained in a narrow windo
w and can serve as additional tool for discriminating radiation from q
uark-gluon matter.