Final state interactions in the decays J/psi->VPP

TL;DR

This paper studies how final state interactions affect decay processes of J/psi into vector and pseudoscalar mesons, revealing that even small interactions can significantly influence decay amplitudes in certain phase space regions.

Contribution

It demonstrates that crossed channel final state interactions, constrained by unitarity, can notably impact decay amplitudes, challenging previous assumptions about their negligible effects.

Findings

Crossed channel interactions influence decay amplitudes in specific phase space areas.

Unitarity constraints remain relevant for production amplitudes.

Small interactions can have significant effects in certain conditions.

Abstract

We investigate the interplay between crossed channel final state interactions and the constraints from two--particle unitarity for the reactions J/psi->V pi pi and VK\bar K, where V is either omega or phi. Using a model where the parameters are largely constrained by other sources, we find that, although small, crossed channel final state interaction can influence the amplitudes considerably, in special areas of phase space. These results cast doubt on the inapplicability of unitarity constraints on production amplitudes as recently claimed in the literature.