No-scale supersymmetry breaking vacua and soft terms with torsion

TL;DR

This paper investigates no-scale supersymmetry breaking vacua in type IIA and IIB supergravity compactifications with SU(3)-structure, focusing on torsion-induced breaking, soft terms, and phenomenological implications.

Contribution

It identifies conditions for no-scale supersymmetry breaking driven by intrinsic torsion and computes resulting soft terms for various D-brane configurations.

Findings

Gravitino mass in type IIB is governed by torsion class W_1.

Two classes of solutions in type IIA with different mediation mechanisms.

Computed geometrically induced mu-terms for D-branes on twisted tori.

Abstract

We analyze the conditions to have no-scale supersymmetry breaking solutions of type IIA and IIB supergravity compactified on manifolds of SU(3)-structure. The supersymmetry is spontaneously broken by the intrinsic torsion of the internal space. For type IIB orientifolds with O9 and O5-planes the mass of the gravitino is governed by the torsion class W_1, and the breaking is mediated through F-terms associated to descendants of the original N=2 hypermultiplets. For type IIA orientifolds with O6-planes we find two families of solutions, depending on whether the breaking is mediated exclusively by hypermultiplets or by a mixture of hypermultiplets and vector multiplets, the latter case corresponding to a class of Scherk-Schwarz compactifications not dual to any geometric IIB setup. We compute the geometrically induced mu-terms for D5, D6 and D9-branes on twisted tori, and discuss the patterns of soft-terms which arise for pure moduli mediation in each type of breaking. As for D3 and D7-branes in presence of 3-form fluxes, the effective scalar potential turns out to possess interesting phenomenological properties.