Leptonic and Charged Kaon Decay Modes of the Meson Measured in Heavy-Ion Collisions at the CERN Super Proton Synchrotron

We report on results of a measurement of meson production in central Pb-Au collisions at E_lab=158A GeV. For the first time in the history of high energy heavy-ion collisions, mesons were reconstructed both in the K⁺K^- and the dilepton decay channels in the same experiment. This measurement yields rapidity densities near midrapidity, from the two decay channels, of 2.05±0.14(stat)±0.25(syst) and 2.04±0.49(stat)±0.32(syst), respectively. The shape of the measured transverse momentum spectrum is also in close agreement in both decay channels. The data rule out a possible enhancement of the yield in the leptonic over the hadronic decay channel of a factor 1.6 or larger at the 95% C.L. This rules out the discrepancy reported in the literature between measurements of the hadronic and dimuon decay channels by two different experiments.

©2006 The American Physical Society