Tests of factorization inD,Ds+, andBdecays

We have tested the factorization hypothesis by comparing B(${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathrm{\rho }}^{+}$), B(${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathit{a}}_1^{+}$), and B(${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathrm{\pi }}^{+}$) with B(${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathit{e}}^{+}$ν), and B(${\mathit{D}}^0$→${\mathrm{\pi }}^{+}$ ${\mathrm{\pi }}^{\mathrm{-}}$) with B(${\mathit{D}}^0$→${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathit{e}}^{+}$ν). In all cases except ${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathit{a}}_1^{+}$ we find that the factorization hypothesis works once final-state interactions are taken into account. ${\mathit{D}}^0$→${\mathit{K}}^{\mathrm{-}}$ ${\mathit{a}}_1^{+}$ remains a problem. We have also predicted B(${\mathit{D}}_{\mathit{s}}^{+}$→${\mathit{K}}^0$ ${\mathit{e}}^{+}$ν) by relating it to B(${\mathit{D}}_{\mathit{s}}^{+}$→${\mathit{K}}^{+}$K${\mathrm{¯}}^{\mathrm{*}0}$) and B(${\mathit{D}}_{\mathit{s}}^{+}$→(η,η’)${\mathit{e}}^{+}$ν) by relating them to B(${\mathit{D}}_{\mathit{s}}^{+}$→(η,η’)${\mathrm{\rho }}^{+}$). Finally, we discuss tests of factorization in ${\mathit{B}}^0$→${\mathrm{\pi }}^{+}$ ${\mathrm{\pi }}^{\mathrm{-}}$ by relating it to ${\mathit{B}}^0$→${\mathrm{\pi }}^{\mathrm{-}}$ ${\mathit{e}}^{+}$ν.