Classical and Quantum SUSY Breaking Effects in IIB Local Models

TL;DR

This work analyzes soft SUSY-breaking terms in Type IIB LVS compactifications with MSSM sectors on D3/D7 branes. Classical soft terms are highly volume-suppressed and, without uplift, gaugino masses are negligible; uplift via dilaton/complex-structure F-terms and Weyl anomaly corrections become crucial, with AMSB-like gaugino masses dominating. The gaugino masses induce scalar masses through RG evolution (gaugino mediation), generally yielding TeV-scale sparticles when the gravitino mass lies in the tens-to-hundreds of TeV range. FCNC constraints require a large compactification volume, but quantum effects relax the naive bound, allowing viable scenarios with sequestered SUSY breaking, albeit with a cosmological modulus problem that motivates further tuning or heavier gravitino. Overall, LVS provides a UV-complete, predictive framework for SUSY breaking with distinctive phenomenology driven by anomaly mediation and RG effects.

Abstract

We discuss the calculation of soft supersymmetry breaking terms in type IIB string theoretic models in the Large Volume Scenario (LVS). The suppression of FCNC gives a lower bound on the size of the compactification volume. This leads to soft terms which are strongly suppressed relative to the gravitino mass so that the dominant contribution to the gaugino masses comes from the Weyl anomaly. The other soft terms are essentially generated by the renormalization group running from the string scale to the TeV scale.