Interesting four-quark states besidesξ(2220)

We point out the the four-quark (ss¯ss¯) $0^{++}$ interpretation of the ξ(2220) state anticipates other narrow $0^{++}$ states near thresholds for (ss¯cc¯), (cc¯cc¯), (ss¯bb¯), (cc¯bb¯), and (bb¯bb¯). The most accessible state may be the (cc¯cc¯) state near 8 GeV, which can be produced in Υ→$0^{++}$(cc¯cc¯)+γ with a branching ratio B(Υ→$0^{++}$+γ) at the level of 1×${10}^{\mathrm{-}4}$ or a little lower.