Baryon-antibaryon threshold and ω-baryonium mixing

Abstract

It is shown that in any dual-topological-unitarization model of ω-baryonium (B) mixing at the cylinder level, in which the production of baryon-antibaryon (bb^- ) pairs can take place only above a certain threshold energy, the phenomenologically relevant ω and B frajectories do not mix below bb^- threshold. However, their couplings to external particles do get modified. The ω-B mixing angle θ_ω-B, which characterizes these coupling modification effects below bb^- threshold at t=0, is estimated in some models. These estimates are found to agree reasonably well with the existing phenomenological bound on θ_ω-B.