BABAR resonance as a new window of hadron physics

The possible decays of four-quark mesons are studied by assigning the newly observed BABAR resonance to a four-quark meson, $F_I^{+}\sim \left[\mathrm{cq}\right]\left[\overline{s}\overline{q}\right]$ with $q=u,d.\mathrm{}$ It is expected that some of them can be observed as narrow resonances. The implication of the existence of four-quark mesons in hadronic weak interactions is also discussed.