Final-state interaction phase difference in $J/ψ\toρη$ and $ωη$ decays

Abstract

It is shown that the study of the $ω-ρ^0$ interference pattern in the $J/ψ\to (ρ^0+ω)η\toπ^+π^-η$ decay provides the evidence for the large (nearly $90^\circ$) relative phase between the one-photon and the three-gluon decay amplitudes.