Sequestered de Sitter String Scenarios: Soft-terms

TL;DR

This paper investigates soft supersymmetry breaking in type IIB de Sitter string vacua with sequestered Standard Model sectors, revealing two phenomenological scenarios with distinct soft-term hierarchies compatible with unification and TeV-scale SUSY.

Contribution

It provides the first detailed analysis of soft-terms in fully stabilized string models within a compact Calabi-Yau, exploring phenomenological implications of different de Sitter vacua constructions.

Findings

Two phenomenological scenarios: split-supersymmetry and MSSM-like soft-term spectrum.

Soft-terms depend on moduli and fluxes, allowing parameter tuning.

Models are compatible with gauge unification and TeV-scale supersymmetry.

Abstract

We analyse soft supersymmetry breaking in type IIB de Sitter string vacua after moduli stabilisation, focussing on models in which the Standard Model is sequestered from the supersymmetry breaking sources and the spectrum of soft-terms is hierarchically smaller than the gravitino mass $m_{3/2}$. Due to this feature, these models are compatible with gauge coupling unification and TeV scale supersymmetry with no cosmological moduli problem. We determine the influence on soft-terms of concrete realisations of de Sitter vacua constructed from supersymmetric effective actions. One of these scenarios provides the first study of soft-terms for consistent string models embedded in a compact Calabi-Yau manifold with all moduli stabilised. Depending on the moduli dependence of the Kaehler metric for matter fields and on the mechanism responsible to obtain a de Sitter vacuum, we find two scenarios for phenomenology: (i) a split-supersymmetry scenario where gaugino masses are suppressed with respect to scalar masses: $M_{1/2} \sim m_{3/2} \epsilon \ll m_0 \sim m_{3/2} \sqrt{\epsilon} \ll m_{3/2}$ for $\epsilon \sim m_{3/2}/M_P \ll 1$; (ii) a typical MSSM scenario where all soft-terms are of the same order: $M_{1/2} \sim m_0 \sim m_{3/2} \epsilon \ll m_{3/2}$. Background fluxes determine the numerical coefficients of the soft-terms allowing for small variations of parameters as is necessary to confront data and to interpolate between different scenarios. We comment on different stringy origins of the mu-term and potential sources of desequestering.