D0→φK¯0decay in the algebraic approach to nonleptonic weak decays

Contrary to the expectation of the naive spectator model, $D^0$→φK${¯}^0$ decay has recently been observed with an appreciable branching ratio. In this paper, it is however pointed out that the sizable rate of $D^0$→φK${¯}^0$ decay is, in fact, no surprise in the newly developed algebraic approach to nonleptonic weak interactions and it can be estimated from the well-known rate of $K_S$→2π decays. The value of Γ($D^0$→φK${¯}^0$) thus obtained is in good agreement with experiments. The approach uses a hard-pseudoscalar-meson extrapolation instead of a soft one and deals with long-distance physics in earnest, by using the algebraic method developed in the framework of asymptotic flavor symmetry which nevertheless maintains a close connection with quark-line diagrams.