A string landscape guide to soft SUSY breaking terms

TL;DR

This paper explores how the string theory landscape influences the distribution of soft SUSY breaking terms, proposing a statistical framework that predicts non-universal scalar masses and their implications for particle physics phenomenology.

Contribution

It introduces a predictive landscape framework where soft SUSY terms scan independently, leading to natural explanations for non-universality and addressing SUSY flavor and CP problems.

Findings

Soft terms follow a power-law distribution favoring larger values.

Non-universality of scalar masses emerges as a natural feature.

Predictions for Higgs and sparticle masses inform LHC and dark matter searches.

Abstract

We examine several issues pertaining to statistical predictivity of the string theory landscape for weak scale supersymmetry (SUSY). We work within a predictive landscape wherein super-renormalizable terms scan while renormalizable terms do not. We require stringy naturalness wherein the likelihood of values for observables is proportional to their frequency within a fertile patch of landscape including the MSSM as low energy effective theory with a pocket-universe value for the weak scale nearby to its measured value in our universe. In the string theory landscape, it is reasonable that the soft terms enjoy a statistical power-law draw to large values, subject to the existence of atoms as we know them (atomic principle). We argue that gaugino masses, scalar masses and trilinear soft terms should each scan independently. In addition, the various scalars should scan independently of each other unless protected by some symmetry. The expected non-universality of scalar masses-- once regarded as an undesirable feature-- emerges as an asset within the context of the string landscape picture. In models such as heterotic compactifications on Calabi-Yau manifolds, where the tree-level gauge kinetic function depends only on the dilaton, then gaugino masses may scale mildly, while scalar masses and A-terms, which depend on all the moduli, may scale much more strongly leading to a landscape solution to the SUSY flavor and CP problems in spite of non-diagonal K\"ahler metrics. We present numerical results for Higgs and sparticle mass predictions from the landscape within the generalized mirage mediation SUSY model and discuss resulting consequences for LHC SUSY and WIMP dark matter searches.