ELECTROMAGNETIC FORM-FACTOR OF D-ASTERISK-]D TRANSITION IN THE TIME-LIKE REGION

The internal conversion process D --> De(+) e(-), and D*($) over bar D-pair production in e(+) e(-) -collisions, e(+) e(-) --> D($) over b ar D, which are described by the same electromagnetic form factor with time-like momentum transfer, have been analyzed. After carrying out a general analysis of the kinematical aspects of the one-photon mechani sm has been performed and the predictions of the vector-dominance mode l for the D --> D transition form factor are discussed. It is shown t hat use of the asymptotic behaviour of the form factors of D(+,0) --> D(+,0)gamma-transitions and the theoretical values of constants of D (+,0) --> D(+,0)gamma radiative decay enables one to determine part o f the unknown parameters of these form factors. The coefficient of the internal conversion for D --> De(+) e(-) is calculated and is shown to be model independent.