Measurements of charmed-meson production in interactions between 350 GeV/c π− particles and nuclei Original Research Article

Charmed-meson production by 350 GeV/c π− particles incident on copper and tungsten targets has been studied in the WA92 experiment, performed at the CERN Ω′ spectrometer. Results obtained are reported and discussed. Reconstruction of decays from the set D0 → K−π+ D0 → K−π−π+π+, Ds+ → φπ+ and charge conjugates has yielded a sample of 7280 ± 108 charmed mesons, produced with χF > 0, (χF) = 0.18 and〈pT2〉 = 1.86 (GeV/c)2. Assuming a relationship σ = σ0Aα between the cross section, σ, per nucleus of mass A and the nucleonic cross section, σ0 the α value found for the detected charmed particles is 0.95 ± 0.06 ± 0.03. Taking α = 1, the measured cross sections per nucleon for χF > 0 production are 7.78 ± 0.14 ± 0.52 μb for D0/D0, 3.28 ± 0.08 ± 0.29 μb for D+/D− and 1.29 ± 0.16 ± 0.33 μb for Ds+/Ds−. Differential cross sections with respect to χF and pT2 have been determined for the various types of charmed meson, and particle-antiparticle asymmetries have been analysed.