Flavor Symmetry and Decays of Charmed Mesons to Pairs of Light Pseudoscalars

The application of SU(3) flavor symmetry to charmed particle decays can shed light on such questions as the strong phases of amplitudes in these decays. Such strong phases are non-negligible even in B decays to pairs of pseudoscalar mesons (P ), and can be even more important in D → PP decays. In the present paper we shall extract strong phases from charmed particle decays using SU(3) flavor symmetry, primarily the U-spin symmetry involving the interchange of s and d quarks. A preliminary version of this work was presented in Ref. [1]. We recall the diagrammatic approach to flavor symmetry in Section 2. We then treat Cabibbo-favored decays in Section 3, turning to singly-Cabibbo-suppressed decays in Section 4 and doubly-Cabibbo-suppressed decays in Section 5. We mention some other theoretical approaches in Section 6, and conclude in Section 7.