Quasi-two-body decays in perturbative QCD*

Abstract

Abstract In this work, we investigate the quasi-two-body decays with using the perturbative QCD (PQCD) approach. The description of final state interactions of the pair is achieved through the two-meson distribution amplitudes (DAs), which are normalized to the time-like form factor. The PQCD predictions on the branching ratios of the quasi-two-body decays show an obvious hierarchy: and . From the invariant mass -dependence of the decay spectrum for each channel, one can find that the branching fraction is concentrated in a narrow region around the pole mass. Thus, one can obtain the branching ratios for the corresponding two-body decays under the narrow-width approximation. We find that the branching ratios of the decays are consistent with the previous PQCD calculations within errors. These predictions will be tested in future experiments.