Sequestering in String Compactifications

TL;DR

This paper examines whether geometric separation in string compactifications effectively isolates visible and hidden sectors for supersymmetry breaking, finding that nonperturbative effects often introduce cross-couplings that challenge sequestering.

Contribution

It critically analyzes sequestering in string theory, showing that nonperturbative superpotentials generally induce cross-couplings, and identifies conditions under which sequestering can be maintained.

Findings

Nonperturbative superpotentials break sequestering in type IIB compactifications.

In the Large Volume Scenario, superpotential effects can cause flavor violation.

KKLT compactifications have negligible superpotential effects on sequestering.

Abstract

We study the mediation of supersymmetry breaking in string compactifications whose moduli are stabilized by nonperturbative effects. We begin with a critical review of arguments for sequestering in supergravity and in string theory. We then show that geometric isolation, even in a highly warped space, is insufficient to achieve sequestering: in type IIB compactifications, nonperturbative superpotentials involving the Kahler moduli introduce cross-couplings between well-separated visible and hidden sectors. The scale of the resulting soft terms depends on the moduli stabilization scenario. In the Large Volume Scenario, nonperturbative superpotential contributions to the soft trilinear $A$ terms can introduce significant flavor violation, while in KKLT compactifications their effects are negligible. In both cases, the contributions to the $\mu$ and $B\mu$ parameters cannot be ignored in general. We conclude that sequestered supersymmetry breaking is possible in nonperturbatively-stabilized compactifications only if a mechanism in addition to bulk locality suppresses superpotential cross-couplings.