The Gluonic Decay of the b – Quark and the η ′ – Meson ∗

The observed inclusive decay of B–mesons into η′ + X is interpreted as the consequence of the gluonic decay of the b–quark into an s–quark. As a result of the QCD anomaly this decay proceeds partly as the decay b → s + η′, similar to b → s + J/ψ. The hadronic recoiling system is found to have a relatively large mass. Analogously one expects a decay of the type b→ s+ σ. The branching ratios for these decays are large (of the order of 10 %). The results indicate that there is no room for an anomalously large chromomagnetic decay mode of the b–quark. Gluon jets are expected to exhibit an anomalously large tendency to fragment into η′and σmesons. LMU 08/97 CERN-TH/97-200 ∗Supported in part by GIF contract I 0304–120.07/93 and EEC contract CHRX–CT94–0579