Soft Supersymmetry Breaking in Calabi-Yau Orientifolds with D-branes and Fluxes

TL;DR

This paper derives the effective N=1 supergravity action for D3-branes in type IIB Calabi-Yau orientifolds with fluxes, revealing the structure of soft supersymmetry breaking terms and their universal scalar masses.

Contribution

It provides the first detailed computation of the Kahler potential and soft terms for D3-branes in flux compactifications, including couplings to bulk moduli.

Findings

Universal soft scalar masses in the effective theory

Explicit form of the Kahler potential for D-brane excitations

Fluxes induce spontaneous supersymmetry breaking

Abstract

In this paper we compute the N=1 effective low energy action for a stack of N space-time filling D3-branes in generic type IIB Calabi-Yau orientifolds with non-trivial background fluxes by reducing the Dirac-Born-Infeld and Chern-Simons actions. Specifically, we determine the Kahler potential for the excitations of the D-brane including their couplings to all bulk moduli fields. In the effective theory, N=1 supergravity is spontaneously broken by the presence of fluxes and we compute the induced soft supersymmetry breaking terms. We find an interesting structure in the resulting soft terms with generically universal soft scalar masses.