RESONANT SUBSTRUCTURE IN KBAR-PI-PI-PI DECAYS OF D-MESONS

We determine the resonant substructure of D --> K-pi-pi-piBAR decays, extracting the relative fractions and phases of the amplitudes contrib uting to the K- pi+pi+pi-, K0BAR pi+pi+pi-, K- pi+pi+pi(0), and K0BAR pi+pi-pi(0) final states. We find that two-body decay modes account fo r at least 75% of these decays. We obtain branching ratios for D --> K a1BAR (1260), D --> KBAR rho, D --> K1BAR (1270)pi, D --> K1BAR (1400 )pi, and D0 --> K0omegaBAR decay modes, as well as for several three- and four-body decay modes. In the case of D --> Ka1BAR (1260) and D -- > KBAR rho, we obtain the branching ratios for all three possible iso spin combinations, enabling us to extract the isospin-1/2 and -3/2 amp litudes, and their relative phases. We find that the isospin-3/2 ampli tudes are suppressed relative to the isospin-1/2 amplitudes. This impl ies that the widths of the D+ modes are suppressed relative to those o f the D0, confirming that an understanding of the lifetime difference of the D0 and D+ depends on an understanding of two-body hadronic deca ys. For the D --> KBAR rho decay modes, we obtain detailed informatio n on the polarization of the KBAR and rho. This enables us to place c onstraints on the form factors for D --> KBAR and D --> rho-transitio ns. A comparison of our results on D --> KBAR rho decays with recent results on semileptonic decays allows us to test the factorization hyp othesis.