Scattering of twist fields from D-branes and orientifolds

TL;DR

This paper calculates two-point functions of twist fields in orbifold string theories and applies these results to determine one-loop corrections to the Kahler potential and Fayet-Iliopoulos terms in type I string models, revealing non-vanishing corrections away from the orbifold point.

Contribution

It provides explicit computations of twist field correlators on disk and RP2 and connects these to physical corrections in string compactifications, extending understanding of quantum effects in orbifold models.

Findings

Computed two-point functions for twist fields on disk and RP2.

Derived one-loop corrections to Kahler potential in type I string theory.

Found non-zero corrections to Fayet-Iliopoulos terms away from the orbifold point.

Abstract

We compute the two-point function for Z_N orbifold twist fields on the disk and RP2. We apply this to a computation of the O(g_s) correction to the Kahler potential for (the symmetric combination of) blow-up modes in type I string theory on T^6/Z_3. This is related by supersymmetry to the one-loop field dependent correction to the Fayet-Iliopoulos D-term for the anomalous U(1) factor. We find this correction to be non-vanishing away from the orbifold point.