SUSY breaking in local string/F-theory models
Abstract
We investigate bulk moduli stabilisation and supersymmetry breaking in local string/F-theory models where the Standard Model is supported on a del Pezzo surface or singularity. Computing the gravity mediated soft terms on the Standard Model brane induced by bulk supersymmetry breaking in the LARGE volume scenario, we explicitly find suppressions by Ms/MP ~ Script V-1/2 compared to M3/2. This gives rise to several phenomenological scenarios, depending on the strength of perturbative corrections to the effective action and the source of de Sitter lifting, in which the soft terms are suppressed by at least MP/Script V3/2 and may be as small as MP/Script V2. Since the gravitino mass is of order M3/2 ~ MP/Script V, for TeV soft terms all these scenarios give a very heavy gravitino (M3/2 >= 108 GeV) and generically the lightest moduli field is also heavy enough (m >= 10 TeV) to avoid the cosmological moduli problem. For TeV soft terms, these scenarios predict a minimal value of the volume to be Script V ~ 106-7 in string units, which would give a unification scale of order MGUT ~ MsScript V1/6 ~ 1016 GeV. The strong suppression of gravity mediated soft terms could also possibly allow a scenario of dominant gauge mediation in the visible sector but with a very heavy gravitino M3/2 > 1 TeV.
- Publication:
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Journal of High Energy Physics
- Pub Date:
- September 2009
- DOI:
- 10.1088/1126-6708/2009/09/007
- arXiv:
- arXiv:0906.3297
- Bibcode:
- 2009JHEP...09..007B
- Keywords:
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- High Energy Physics - Theory
- E-Print:
- JHEP 0909:007,2009