On Wess-Zumino terms of brane-antibrane systems

We calculate the disk level S-matrix element of one closed string RR field, two open string tachyons and one gauge field in type II superstring theory. An expansion for the S-matrix element has been found that its four leading order terms are reproduced exactly by the symmetric trace tachyon DBI and the Wess-Zumino actions of D-brane-anti-D-brane systems. Using this consistency, we have also found the first higher derivative correction to the some of the WZ terms.