Note on invisible decays of light mesons.

A search for the invisible decays of ω and ϕ mesons in J/ψ→ω(ϕ)η transitions was performed by the BESIII Collaboration very recently. Inspired by this experimental study, we compute the lowest-order contribution to branching ratios of B(V→¯νν) with V denoting ρ, ω, ϕ, as the standard model background to these invisible decays. Our predictions are far below the upper bounds given by the BESIII experiment. We also analyze the J/ψ→η(η′)¯νν processes and estimate their decay rates. Furthermore, the invisible decays of light pseudoscalar mesons P including π0, η, and η′ are reexamined in the present paper. It is shown that, due to the helicity suppression of the two-neutrino final state, the standard model contributions to P→invisible decays are dominated by P→¯νν¯νν processes. [ABSTRACT FROM AUTHOR]