Radiative weak decays of charm mesons.

We address standard model predictions for flavor-changing radiative transitions of the pseudoscalar charm mesons. Short-distance contributions in {ital D} radiative transitions are contrasted with those in {ital B} decays. A full analysis is presented of the {ital c}{r_arrow}{ital u}+{gamma} electromagnetic penguin amplitude with QCD radiative corrections included. Given the importance of long-range effects for the charm sector, special attention is paid to such contributions as the vector dominance and pole amplitudes. A number of two-body final states in exclusive charm radiative decays is considered and the corresponding branching ratio predictions are given.