On RR Couplings and Bulk Singularity Structures of Non-BPS Branes

TL;DR

This paper calculates a detailed five-point string scattering amplitude involving RR fields, scalars, gauge fields, and tachyons on non-BPS branes, revealing new bulk singularity structures and Bianchi identities.

Contribution

It provides the first complete analysis of the <C^{-1} al^0 A^0 T^{-1}> S-matrix, uncovering new bulk singularity structures and restricted Bianchi identities in superstring theory.

Findings

Identified u' and t channel bulk singularities in the amplitude.

Analyzed the amplitude in both world volume and transverse directions.

Proposed new restricted Bianchi identities on the world volume.

Abstract

We compute the five point world sheet scattering amplitude of a symmetric closed string Ramond-Ramond , a transverse scalar field, a world volume gauge field and a real tachyon in both world volume and transverse directions of brane in type IIA and IIB superstring theory. We provide the complete analysis of $<C^{-1} \phi^0 A^0 T ^{-1}>$ S-matrix and show that both $u'=u+\frac{1}{4}$ and $t$ channel bulk singularity structures can also be examined by this S-matrix. Various remarks about new restricted Bianchi identities on world volume for the other pictures have also been made.