Scanning of the Supersymmetry Breaking Scale and the Gravitino Mass in Supergravity

TL;DR

This paper explores how three-form fields in supergravity can dynamically scan and adjust the supersymmetry breaking scale and gravitino mass, potentially explaining a small cosmological constant despite large underlying scales.

Contribution

It introduces a mechanism where membrane nucleation of three-forms in supergravity scans key parameters, affecting the cosmological constant and supersymmetry breaking.

Findings

Membrane nucleation can dynamically vary the supersymmetry breaking scale.

The gravitino mass is controlled by the three-form of the supergravity multiplet.

The cosmological constant can remain small despite large supersymmetry breaking and gravitino mass.

Abstract

We consider the minimal three-form ${\cal N}=1$ supergravity coupled to nilpotent three-form chiral superfields. The supersymmetry breaking is sourced by the three-forms of the chiral multiplets, while the value of the gravitino mass is controlled by the three-form of the supergravity multiplet. The three-forms can nucleate membranes which scan both the supersymmetry breaking scale and the gravitino mass. The peculiar supergravity feature that the cosmological constant is the sum of a positive contribution from the supersymmetry breaking scale and a negative contribution from the gravitino mass makes the cosmological constant jump. This can lead to a phenomenologically allowed small value of the cosmological constant even though the supersymmetry breaking scale and the gravitino mass are dynamically large.