Direct-photon production in heavy-ion collisions from SPS to RHIC energies

Direct photons are an important tool for the detection of the quark-gluon plasma in ultra-relativistic nucleus-nucleus collisions. Direct-photon measurements were made in Pb + Pb collisions at GeV and in Au + Au collisions at GeV. These results are reviewed and compared with model calculations.Arrival of the final proofs: 9 May 2005PACS: 25.75.DwThis revised version was published online in July 2005 with a correction to the article category and incorporation of the revised date.