Antiproton-nucleon Annihilation intoπoMandηMwithM=η,ω,ρ, andπin Antiproton-deuterium Annihilation at Rest

Using modularized NaI(Tl) detectors, we carried out a high-statistics measurement of inclusive π o and η spectra in antiproton annihilation at rest in a liquid D 2 target. We obtained the following two-meson yields (branching ratios) per \bar p N ( N = p or n ) annihilation: 0.19± 0.09% for π o ω, 1.07±0.19% for π o ρ o , 0.057±0.018% for π o η, 0.0123±0.0055% for π o π o , 0.02±0.02% for π o ρ - , 0.202±0.031% for π o π - , 0.49±0.12% for ηω, 0.45±0.15% for ηρ o , and 0.91±0.22% for ηρ - .