Abstract
A two-component model of the decay , in which the amplitude is the sum of a pion-loop contribution and a vector-meson-mediated term, is compared with data from the NA31 and E731 experiments. An estimate is obtained for the parameter characterizing the strength of the vector-meson component. The amplitude of , determined in this way, is used to calculate the -conserving amplitude of the decays and , without neglect of lepton masses. This complex amplitude (containing both absorptive and dispersive parts) is allowed to interfere with the -violating amplitude expected from the short-distance interaction and from the impurity of the wave function. Results are obtained for the branching ratios of and for the -violating asymmetry in the Dalitz plot.
- Received 16 November 1992
DOI:https://doi.org/10.1103/PhysRevD.47.4920
©1993 American Physical Society