Contribution ofπ0and η Dalitz decays to the dilepton invariant-mass spectrum in1AGeV heavy-ion collisions

The Dalitz-decay contributions of pi(0) and eta mesons to the di-electron invariant-mass spectrum at 1A GeV have been obtained from a systematics of inclusive meson production cross sections measured for the collision systems C-12 + C-nat and Ar-40, Ca-40 + Ca-nat in the bombarding-energy range of 0.8-2.0 A GeV. These results are compared with the recently published di-electron mass spectra of the DLS collaboration. Systematic errors and angular-distribution effects are discussed. We conclude that the low-mass part of the DLS data cannot be explained by the Dalitz decays of light neutral mesons only.