1304.3711 (Ehsan Hatefi)

All order $α'$ higher derivative corrections to non-BPS branes of
type IIB Super string theory    [PDF]

Ehsan Hatefi

By dealing with the evaluation of string theory correlators of $$, the complete and closed form of the amplitude of two fermion fields, one tachyon and one closed string Ramond-Ramond field in type IIB super string theory is found. Specifically by comparing infinite tachyon poles in field theory amplitude with infinite tachyon poles of the S-matrix of string amplitude (for $p+1=n$ case), all the infinite higher derivative corrections of two tachyons and two fermions (in type IIB) to all orders of $\alpha'$ have been discovered. Using these new couplings, we are able to produce infinite $t'+s'+u$-channel tachyon poles of string theory in field theory. Due to internal degrees of freedom of fermions and tachyon (Chan-Paton factors) we comment that, neither there should be single $s,t-$channel fermion (tachyon pole) nor their infinite poles. Due to internal CP factor we also discover that there is no coupling between two closed string Ramond-Ramond field and one tachyon in type II super string theory. Taking into account the fact that the kinetic terms of fermions, gauge, scalar fields and tachyons do not obtain any higher derivative corrections, and due to their CP factors, string theory amplitude dictates us there should not be any double poles in this amplitude. Finally we make some comments on tachyonic action as well as its gauge fixed super symmetric version.

View original: http://arxiv.org/abs/1304.3711