RAPIDITY DEPENDENCE OF THERMAL DILEPTONS RESULTING FROM HADRONIZING QUARK-GLUON MATTER WITH FINITE BARYON CHARGE

The influence of a non-vanishing baryon charge on the rapidity distrib ution of dileptons produced in ultrarelativistic heavy-ion collisions is studied. We employ a frozen motion model with scaling invariant exp ansion of the hadronizing quark-gluon plasma as well as a realistic ra pidity distribution of secondary particles (i.e., pions and baryons) e xpected for RHIC energies. We demonstrate a sizeable suppression of th e thermal dilepton yield at large rapidities due to the finite baryon density. This affects the most favorable rapidity window for using dil eptons for the diagnostic of the quark-gluon plasma and the early temp erature distribution of the hot reaction zone. To discriminate the the rmal dileptons from Drell-Yan background we propose to utilize the dil epton yield scaled suitably by the pion multiplicity as function of ra pidity.