SUSY's Ladder: Reframing Sequestering at Large Volume

TL;DR

This paper explores the hierarchy of mass scales in large volume supersymmetric theories, called SUSY's Ladder, highlighting its phenomenological advantages and deriving its effective field theory from higher-dimensional supergravity models.

Contribution

It introduces SUSY's Ladder as a new hierarchy structure in no-scale models, and demonstrates its origin from specific higher-dimensional theories, providing a novel phenomenological perspective.

Findings

SUSY's Ladder suppresses gaugino masses relative to scalar masses.

The scenario avoids common supersymmetric problems like the gravitino and flavor issues.

Four-dimensional no-scale theories originate from five- and ten-dimensional supergravity.

Abstract

Theories with approximate no-scale structure, such as the Large Volume Scenario, have a distinctive hierarchy of multiple mass scales in between TeV gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a particular realization of Split Supersymmetry in which the same small parameter suppresses gaugino masses relative to scalar soft masses, scalar soft masses relative to the gravitino mass, and the UV cutoff or string scale relative to the Planck scale. This scenario has many phenomenologically interesting properties, and can avoid dangers including the gravitino problem, flavor problems, and the moduli-induced LSP problem that plague other supersymmetric theories. We study SUSY's Ladder using a superspace formalism that makes the mysterious cancelations in previous computations manifest. This opens the possibility of a consistent effective field theory understanding of the phenomenology of these scenarios, based on power-counting in the small ratio of string to Planck scales. We also show that four-dimensional theories with approximate no-scale structure enforced by a single volume modulus arise only from two special higher-dimensional theories: five-dimensional supergravity and ten-dimensional type IIB supergravity. This gives a phenomenological argument in favor of ten dimensional ultraviolet physics which is different from standard arguments based on the consistency of superstring theory.