Abstract
The production of pairs for and is measured in and collisions at . An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central collisions, the excess of the direct photon yield over is exponential in transverse momentum, with an inverse slope . Hydrodynamical models with initial temperatures ranging from at times of after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at .
- Received 25 April 2008
DOI:https://doi.org/10.1103/PhysRevLett.104.132301
©2010 American Physical Society
Viewpoint
Taking the temperature of extreme matter
Published 29 March 2010
Researchers at the Relativistic Heavy Ion Collider have now measured the temperature of hot dense matter created in a nuclear collision.
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