The role of gluons in dilepton production from the quark-gluon plasma

摘要

We study high mass dilepton production from gluon-induced processes, gq --> q gamma *, g (g) over bar --> (q) over bar gamma *, and gg --> q (q) over bar gamma *, in a thermally equilibrated but chemically undersaturated partonic matter that is expected to be created in the initial stage of ultrarelativistic heavy ion collisions. Regulating the divergence in these processes by the thermal quark mass, we find that gluon-induced processes are more important than the leading-order q (q) over bar annihilation process as a result of the larger number of gluons than quarks in the partonic matter. The dependence of the thermal dilepton yield from the partonic stage of heavy ion collisions on the initial conditions for the partonic matter is also studied. We further discuss the feasibility of observing thermal dileptons from the quark-gluon plasma in heavy ion experiments. (C) 2000 Published by Elsevier Science B.V. All rights reserved. [References: 20]