More on Ramond-Ramond, SYM, WZ couplings and their corrections in IIA
  We obtain the closed form of the correlation function of one current and four spin operators (with different chiralities ) in type IIA superstring theory. The complete form of the S-matrix of one gauge , two fermions (with different chiralities) and one closed string Ramond-Ramond for all order $\alpha'$ type IIA has been explored. Moreover, we make use of a different gauge fixing to be able to find out all the closed forms of $<V_{C} V_{A}V_{\bar\psi}V_{\psi} >$ correlators. An infinite number of $t,s-$channel fermion poles of this S-matrix in the field theory of IIA is generated. Unlike the the closed form of the correlators of the same amplitude of IIB, for various $p,n$ cases in type IIA we do have different double poles in $t,(t+s+u)$ and in $s,(t+s+u)$ channels and we produced them. We also find new Wess-Zumino couplings of IIA with their third order $\alpha' $ corrections as well as a new form of higher derivative corrections (with different coefficient from its IIB one ) to SYM couplings at third order of $\alpha' $. Using them, we are able to produce a $(t+s+u)$ channel scalar pole of the $<V_{C} V_{A}V_{\bar\psi}V_{\psi} >$ amplitude for $p+2=n$ case. Finally we make some comments on $\alpha'$ corrections to IIA Superstring theory. 
Ehsan Hatefi
hep-th math-ph math.MP