Equivalent Photon Approach to Simultaneous Excitation in Heavy Ion   Collision
  We apply the Equivalent Photon Approximation to calculate cross sections for the simultaneous excitation of two heavy ions in relativistic collisions. We study especially the excitation of two nuclei to a 1- - state and show that the equations are symmetric with respect to both ions. We also examine the limit in which the excitation energy of one of the nuclei goes to zero, which gives the elastic case. Finally a few remarks about the limits of this approach are made. 
Kai Hencken, Dirk Trautmann, and Gerhard Baur