B decays as spectroscope for charmed four-quark states

The Ds(2320) state recently observed by BaBar in the Ds+π0 channel may be the first of a host of cqq̄q̄ four-quark states. We give a phenomenological account of the masses and decay modes. The isosinglet Ds(2320) state is the only narrow one, dominated by the observed isospin violating decay and less than ∼ 100 keV in width. All other states are expected to decay hadronically. Notable resonances are in doubly charged Ds+π+, D+K+, wrong pairing D+K−, and also Ds+K−, Dη channels. We propose B decays as searching ground for such 4-quark states, which recoil against D̄(∗) meson from B decay, or π+ D̄(∗), K̄ mesons from B̄ decay. Exotic qcc̄q̄ charmonia could also be produced, and may be behind the slow J/ψ bump in inclusive B→J/ψ+X decay.