Antiproton-nucleon Annihilation into π^oM and ηM with M=η, ω, ρ, and π in Antiproton-deuterium Annihilation at Rest

Abstract

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 D₂ target. We obtained the following two-meson yields (branching ratios) per bar p N (N=p or n) annihilation: 0.19± 0.09 0.000000or π^oω, 1.07± 0.19 0.000000or π^oρ^o, 0.057± 0.018 0.000000or π^oη, 0.0123± 0.0055 0.000000or π^oπ^o, 0.02± 0.02 0.000000or π^oρ^-, 0.202± 0.031 0.000000or π^oπ^-, 0.49± 0.12 0.000000or ηω, 0.45± 0.15 0.000000or ηρ^o, and 0.91± 0.22 0.000000or ηρ^-.