Discriminate vector-glueball mixing from other additional dynamics

Determine whether the enhanced $J/\psi\to VP$ decay amplitudes are caused by mixing with a vector glueball or by other additional dynamics, using observables capable of distinguishing these mechanisms.

Background

The paper shows that introducing an independent electromagnetic contribution in the J/ψJ/\psi decay model can be equivalent, under certain assumptions, to introducing mixing between the J/ψJ/\psi and a vector glueball. Because the fitted couplings enter only through combinations of parameters, the present VPVP decay data cannot separately determine the mixing contribution and the non-glueball contribution.

A decisive resolution requires future theoretical or experimental information that breaks this equivalence, such as independent constraints on vector-glueball properties, its couplings, or additional decay observables.

References

These arguments do not mean that the results should be interpreted for or against mixing with a vector glueball. Rather, in these decays we cannot distinguish whether glueball mixing or some other dynamics of the $J/\psi$ is responsible.

— On the failure of the $12\%$ rule in $J/ψ$ and $ψ(2S)$ decays  (2609.24961 - Vereijken et al., 21 Sep 2026) in Section 4, subsection “The vector glueball”