Moduli Stabilisation with Nilpotent Goldstino: Vacuum Structure and SUSY Breaking

TL;DR

This paper develops an effective field theory framework incorporating a nilpotent goldstino superfield to analyze moduli stabilization, SUSY breaking, and phenomenological implications in string compactifications with anti-D3-branes.

Contribution

It introduces a supersymmetric EFT approach to include anti-D3-branes via a nilpotent superfield, enabling computation of soft SUSY breaking terms in KKLT and LVS scenarios.

Findings

Derived soft SUSY breaking terms for matter on D3-branes.

Identified phenomenological scenarios with split soft mass spectra.

Confirmed stability of the system against D3-anti-D3 attraction effects.

Abstract

We study the effective field theory of KKLT and LVS moduli stabilisation scenarios coupled to an anti-D3-brane at the tip of a warped throat. We describe the presence of the anti-brane in terms of a nilpotent goldstino superfield in a supersymmetric effective field theory. The introduction of this superfield produces a term that can lead to a de Sitter minimum. We fix the Kaehler moduli dependence of the nilpotent field couplings by matching this term with the anti-D3-brane uplifting contribution. The main result of this paper is the computation, within this EFT, of the soft supersymmetry breaking terms in both KKLT and LVS for matter living on D3-brane (leaving the D7-brane analysis to an appendix). A handful of distinct phenomenological scenarios emerge that could have low energy implications, most of them having a split spectrum of soft masses. Some cosmological and phenomenological properties of these models are discussed. We also check that the attraction between the D3-brane and the anti-D3-brane does not affect the leading contribution to the soft masses and does not destabilise the system.