Two-body hadronic charmed meson decays

In this work we study the two-body hadronic charmed meson decays, including both the $PP$ and $VP$ modes. The latest experimental data are first analyzed in the diagrammatic approach. The magnitudes and strong phases of the flavor amplitudes are extracted from the Cabibbo-favored decay modes using χ² minimization. The best-fitted values are then used to predict the branching fractions of the singly Cabibbo-suppressed and doubly Cabibbo-suppressed decay modes in the flavor SU(3) symmetry limit. We observe significant SU(3) breaking effects in some of the singly Cabibbo-suppressed channels. In the case of $VP$ modes, we point out that the AP and AV amplitudes cannot be completely determined based on currently available data. We conjecture that the quoted experimental results for both Dₛ⁺→K̄⁰K*+ and Dₛ⁺→ρ⁺η^' are overestimated. We compare the sizes of color-allowed and color-suppressed tree amplitudes extracted from the diagrammatical approach with the effective parameters a₁ and a₂ defined in the factorization approach. The ratio |a₂/a₁| is more or less universal among the D→K̄π, K̄*π, and K̄ρ modes. This feature allows us to discriminate between different solutions of topological amplitudes. For the long-standing puzzle about the ratio Γ(D⁰→K⁺K^-)/Γ(D⁰→π⁺π^-), we argue that, in addition to the SU(3) breaking effect in the spectator amplitudes, the long-distance resonant contribution through the nearby resonance f₀(1710) can naturally explain why D⁰ decays more copiously to K⁺K^- than π⁺π^- through the W-exchange topology. This has to do with the dominance of the scalar glueball content of f₀(1710) and the chiral-suppression effect in the decay of a scalar glueball into two pseudoscalar mesons. The same final-state interaction also explains the occurrence of D⁰→K⁰K̄⁰ and its vanishing amplitude when SU(3) flavor symmetry is exact. Owing to the G-parity selection rule, Dₛ⁺→π⁺ω does not receive contributions from the short-distance W-annihilation and resonant final-state interactions, but it can proceed through the weak decays Dₛ⁺→ρ⁺η^(^') followed by the final-state rescattering of ρ⁺η^(^') into π⁺ω through quark exchange.