EPJ

2021 Impact factor 3.131
EPJ A - Hadrons and Nuclei
Hadrons and Nuclei
Eur. Phys. J. A 7, 391-396

Prompt contributions to the dilepton yield in heavy ion
collisions

J. Hüfner1,2 - Yu.P. Ivanov1,2,3 - B.Z. Kopeliovich2,3 - J. Raufeisen1,2

1 Institut für Theoretische Physik der Universität, Philosophenweg 19, 69120 Heidelberg, Germany
2 Max-Planck Institut für Kernphysik, Postfach 103980, 69029 Heidelberg, Germany
3 Joint Institute for Nuclear Research, Dubna, 141980 Moscow Region, Russia

Received: 1 December 1999 / Revised version: 18 February 2000 Communicated by A. Schäfer

Abstract
The mass spectrum is calculated for those dileptons which are produced in the early phase of a heavy ion collisions via the direct production $N\!N \rightarrow l^+l^-X$ and via the Compton process $G\!N \rightarrow l^+l^-X$ with prompt gluons radiated in preceding $N\!N$ interactions. Both mechanisms produce a mass spectrum which decreases steeply with invariant mass of the l+l- pair and which is below the CERES data for Pb-Au collisions by about one order of magnitude.

PACS
13.85.Qk Inclusive production with identified leptons, photons, or other nonhadronic particles - 24.85.+p Quarks, gluons, and QCD in nuclei and nuclear processes - 12.38.Bx Perturbative calculations - 12.38.Lg Other nonperturbative calculations

Copyright Società Italiana di Fisica, Springer-Verlag 2000

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