Measurement of the p̄d→φn Pontecorvo reaction for antiproton annihilation at rest

Abstract The results of an investigation of the Pontecorvo reaction p d→φn with stopped antiprotons in a gaseous deuterium target at NTP are presented. A very selective dedicated trigger was used to collect a sample of about 8.5×10 6 annihilations. It is found that the annihilation rate is Y( p d→φn)=(3.56±0.20 +0.2 −0.1 )×10 −6 . Comparison with the corresponding value for the ω -meson production demonstrates a large (a factor 40) apparent violation of the OZI rule, even larger than that found in the annihilation on a free nucleon.