Wz Couplings of D-branes and O- Planes

In this short note we review the construction and role of Wess-Zumino couplings of Dirichlet branes and Orientifold planes, and show how these combine to give the Green-Schwarz anomaly cancelling terms. The low energy effective theory of a D-brane has two types of couplings, the Dirac-Born-Infeld (DBI) and Wess-Zumino (WZ) terms. The former describes the coupling of the vector potential and scalars coupling to the NS⊗NS fields, while the latter gives the coupling of the vector potential and the pullback of the curvature fields to the R⊗R potentials. The first D-brane WZ term [1] simply states that a Dp-brane is charged under C(p+1), the p+ 1-form R⊗R potential S WZ = μp ∫