Flux-induced SUSY-breaking soft terms

TL;DR

This paper develops a general framework for calculating SUSY-breaking soft terms on D3-branes in type IIB string backgrounds with fluxes, revealing patterns like dilaton domination and exploring phenomenological implications.

Contribution

It provides explicit formulae for flux-induced SUSY-breaking soft terms and connects them to 4d supergravity, including realistic models with metastable vacua and phenomenological insights.

Findings

Soft terms of order M_s^2/M_p with specific flux configurations.

Dilaton-dominated SUSY-breaking patterns from imaginary anti-selfdual fluxes.

Potential explanation for the weak scale hierarchy via string scale and compactification scale.

Abstract

We describe the computation of SUSY-breaking terms on a D3-brane in a quite general type IIB supergravity background. We apply it to study the SUSY-breaking induced on the D3-brane world-volume by the presence of NSNS and RR 3-form fluxes. We provide explicit general formulae for the SUSY-breaking soft terms valid for the different types of fluxes, leading to different patterns of soft terms. Imaginary anti-selfdual fluxes with G_3 a pure (3,0)-form lead to soft terms corresponding to dilaton-dominated SUSY-breaking. More general SUSY-breaking patterns are discussed, arising from more general fluxes, or from distant anti-D3-branes. The known finiteness properties of dilaton-dominated soft terms are understood in terms of holography. The above results are interpreted in the context of the 4d effective supergravity theory, where flux components correspond to auxiliary fields of e.g. the 4d dilaton and overall volume modulus. We present semirealistic Type IIB orientifold examples with (meta)stable vacua leading to non-vanishing soft terms of the dilaton-domination type. Such models have many of the ingredients of the recent construction of deSitter vacua in string theory. We finally explore possible phenomenological applications of this form of SUSY-breaking, where we show that soft terms are of order M_s^2/M_p. Thus a string scale of order M_s=10^{10} GeV, and compactification scale three orders of magnitude smaller could explain the smallness of the weak scale versus the Planck mass.