Mirage mediation from the landscape

TL;DR

This paper explores how string theory landscape considerations favor a specific SUSY breaking scenario called mirage mediation, predicting particular sparticle spectra and collider signatures.

Contribution

It provides a detailed analysis of mirage mediation arising from the string landscape, including predicted mass spectra and collider phenomenology.

Findings

Predicted a compressed gaugino spectrum with higgsino-like LSP.

Most probable mirage scale around 10^{13}-10^{14} GeV.

SUSY signals expected at high-luminosity LHC via higgsino pair production.

Abstract

Rather general considerations from the string theory landscape suggest a statistical preference within the multiverse for soft SUSY breaking terms as large as possible subject to a pocket universe value for the weak scale not greater than a factor of 2-5 from our measured value. Within the gravity/moduli-mediated SUSY breaking framework, the Higgs mass is pulled to m_h~ 125 GeV while first/second generation scalars are pulled to tens of TeV scale and gauginos and third generation scalars remain at the few TeV range. In this case, one then expects comparable moduli- and anomaly-mediated contributions to soft terms, leading to mirage mediation. For an assumed stringy natural value of the SUSY mu parameter, we evaluate predicted sparticle mass spectra for mirage mediation from a statistical scan of the string landscape. We then expect a compressed spectrum of gauginos along with a higgsino-like LSP. For a linear (quadratic) statistical draw with gravitino mass m_{3/2}~ 20 TeV, then the most probable mirage scale is predicted to be around \mu_{mir}~10^{13} (10^{14}) GeV. SUSY should appear at high-luminosity LHC via higgsino pair production into soft dilepton pairs. Distinguishing mirage mediation from models with unified gaugino masses may have to await construction of an ILC with \sqrt{s}>2m(higgsino).