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Title: High-energy photons from quark-gluon plasma versus hot hadronic gas

Journal Article · · Physical Review, D (Particles Fields); (United States)
;  [1];  [2]
  1. School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota (USA)
  2. Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota (USA)

Photons in the energy range of about one-half to several GeV have been proposed as a signal of the formation of a quark-gluon plasma in high-energy collisions. To lowest order the thermal emission rate is infrared divergent for massless quarks, but we regulate this divergence using the resummation technique of Braaten and Pisarski. Photons can also be produced in the hadron phase. We find that the dominant contribution comes from the reactions {pi}{pi}{r arrow}{rho}{gamma} and {pi}{rho}{r arrow}{pi}{gamma}; the decays {omega}{r arrow}{pi}{gamma} and {rho}{r arrow}{pi}{pi}{gamma} are also significant. Comparing the thermal emission rates at a temperature {ital T}=200 MeV we conclude that the hadron gas shines just as brightly as the quark-gluon plasma.

DOE Contract Number:
FG02-87ER40328
OSTI ID:
6103274
Journal Information:
Physical Review, D (Particles Fields); (United States), Vol. 44:9; ISSN 0556-2821
Country of Publication:
United States
Language:
English