Measurement of gamma rays from antiproton-deuterium annihilation at rest

Using modularized NaI(Tl) detectors, we have carried out a high-statistics measurement of inclusive {gamma}-ray spectra from {ital {bar p}d} annihilation at rest separately for each charge multiplicity of the final state. We have not seen, at statistical significance above 4{sigma}, any monochromatic {gamma}-ray peaks, which may be assigned to baryonium production {ital {bar p}p} or {ital {bar p}n}{r arrow}{gamma}{ital B} or to {ital {bar N}NN} bound-state production {ital {bar p}d}{r arrow}{gamma}({ital {bar N}NN}). The 4{sigma} upper limit for baryonium production per annihilation varied between 10{sup {minus}2} and 10{sup {minus}4} depending on baryonium mass of 1700 to 600 MeV/{ital c}{sup 2} and on the charge multiplicity. At (2--3){sigma} levels, however, five peaks were observed and three of them are located at the same position with the similar (2--3){sigma} peaks observed in {ital {bar p}p}{r arrow}{gamma}{ital B} and {ital {bar p}p}{r arrow}{pi}{sup 0}{ital B}.