Electric charge fluctuations in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV

Results are presented on event-by-event electric charge fluctuations in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV. The observed fluctuations are close to those expected for a gas of pions correlated by global charge conservation only. These fluctuations are considerably larger than those calculated for an ideal gas of deconfined quarks and gluons. The present measurements do not necessarily exclude reduced fluctuations from a quark-gluon plasma because these might be masked by contributions from resonance decays.