Ramond-Ramond Central Charges in the Supersymmetry Algebra of the Superstring
arXiv:hep-th/9706024 · doi:10.1103/PhysRevLett.79.1813
Abstract
The free action for the massless sector of the Type II superstring was recently constructed using closed RNS superstring field theory. The supersymmetry transformations of this action are shown to satisfy an N=2 D=10 SUSY algebra with Ramond-Ramond central charges.
10 pages harvmac tex