Mildly sequestered supergravity models and their realization in string theory

TL;DR

This paper explores how certain supergravity and string theory models can maintain a form of sequestering despite contact interactions, using global symmetries to prevent soft scalar masses, with implications for supersymmetry breaking scenarios.

Contribution

It demonstrates a mechanism for mild sequestering in supergravity and string models via global symmetries, especially in heterotic M-theory orbifolds, and discusses its implications for dilaton domination.

Findings

Global symmetries can suppress soft scalar masses despite contact interactions.

The mechanism is effective up to subleading effects suppressed by symmetry breaking scales.

It enables dilaton domination scenarios to be compatible with stabilization.

Abstract

We elaborate on the idea that five-dimensional models where sequestering is spoiled due to contact interactions induced by vector multiplets may still be mildly sequestered if a global version of the gauge symmetry associated to the latter survives in the hidden sector. Interestingly, it has been argued that although in such a situation non-trivial current-current contact interactions are induced by the heavy vector modes, these do not induce soft scalar masses, as a consequence of the global symmetry. We perform a detailed study of how this hybrid mechanism can be implemented in supergravity and string models, focusing on the prototypical case of heterotic M-theory orbifolds. We emphasize that in general the mechanism works only up to subleading effects suppressed by the ratio between the global symmetry breaking scale in the hidden sector and the vector mass scale or the Planck scale. We also argue that this mild sequestering mechanism allows to rehabilitate the scenario of dilaton domination of supersymmetry breaking, which is incompatible with dilaton stabilization in its original version, by exploiting the fact that hidden brane fields do contribute to the cosmological constant but not to soft terms, thanks to the global symmetry.