Nonleptonic Decays of Charmed Mesons under the W-Exchange Dominance Hypothesis

摘要

Two- and three-body decays of charmed mesons are studied under the W-exchange dominance hypothesis. As for the two-body decays, the branching ratios for them are calculated in the scalar meson pole approximation. It is seen through a phenomenological analysis that the contribution of the annihilation diagram is much smaller than that of the W-exchange as has been expected in terms of 1/N expansion. This predicts that the F exp + implies pi exp + eta decay is considerably suppressed although it is a Cabibbo favored decay. It is also seen that the new Cabibbo angle theta/sub c/' which is defined in the charm changing currents is nearly equal to the old one theta/sub c/. The soft meson technique combined with a linear approximation is applied to the three-body decays. The calculated value of B(D exp + implies pi exp + pi exp + K exp - ) reproduced considerably well the experimental value, but this method is not successful in the other three-body decays of D mesons. The branching ratios for these decays calculated by assuming that quasi two-body decays contribute dominantly to these decays are almost consistent with the known data. (Atomindex citation 13:660821)