Anomalous couplings for D-branes and O-planes
  We study anomalous Wess-Zumino couplings of D-branes and O-planes in a general background and derive them from a direct string computation by factorizing in the RR channel various one-loop amplitudes. In particular, we find that Op-planes present gravitational anomalous couplings involving the Hirzebruch polynomial L, similarly to the roof genus A encoding Dp-brane anomalous couplings. We determine, in each case, the precise dependence of these couplings on the curvature of the tangent and normal bundles. 
Jose F. Morales, Claudio A. Scrucca and Marco Serone