Electromagnetic Interactions in Heavy Hadron Chiral Theory
  Electromagnetic interactions are incorporated into Heavy Hadron Chiral Perturbation Theory. Short and long distance magnetic moment contributions to the chiral Lagrangian are identified, and $M1$ radiative decays of heavy vector mesons and sextet baryons are studied. Using recent CLEO $D^*$ branching fraction ratio data, we fit the meson coupling to the axial vector Goldstone current and find $g_1^2 = 0.34 \pm 0.48$ for $\mc = 1700 \MeV$. Finally, we obtain model independent predictions for total and partial widths of charm and bottom vector mesons. 
Peter Cho and Howard Georgi