String landscape guide to soft SUSY breaking terms

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 superrenormalizable 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 minimal supersymmetric standard model 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 nonuniversality 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, 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 nondiagonal Kähler 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 weakly interacting massive particles dark matter searches.

Radiative natural supersymmetry emergent from the string landscape

“…A final consideration is whether all soft terms should have common probability distributions on the landscape [51]. For instance, gaugino masses arise from the SUGRA gauge kinetic function f AB which is typically of the form ∼ k • Sδ AB in string models where S is the dilaton superfield and k is some constant.…”

“…6, then this would give a linear draw to large m 1/2 while scalar masses which arise from the Kähler function might have a stronger draw to large values. In addition, the other soft terms such as A 0 have very different dependencies on SUSY breaking fields and hence are expected to scan independently on the landscape [51]. For the bulk of this work, we will generally assume a single source of SUSY breaking so all soft terms scan linearly in m sof t to large values.…”

Moduli stabilisation and the statistics of axion physics in the landscape

“…Despite the difficulty to achieve this goal, scaling arguments and approximate symmetries inherited from the 10D theory [6] could be used as a powerful guideline to shed light on larger portions of the string landscape. This top-down analysis of the statistical properties of quantities relevant for phenomenology is crucial to provide more theoretical guidance to recent bottom-up approaches to understand naturalness and string theory predictions for several observables [55][56][57][58][59][60].…”

Improved $${(g-2)_\mu }$$ measurements and wino/higgsino dark matter

“…• (A) Higgsino DM This scenario is characterized by a small value of μ (as favored, e.g., by naturalness argu-ments [108][109][110][111][112][113]). 3 Such a scenario is also naturally realized in Anomaly Mediation SUSY breaking (see e.g.…”