Goldstini

TL;DR

This paper explores a framework with multiple supersymmetry-breaking sectors leading to multiple goldstini, which can significantly alter supersymmetric phenomenology, collider signatures, and dark matter scenarios.

Contribution

It introduces the concept of multiple goldstini from independent SUSY-breaking sectors and analyzes their universal mass and phenomenological implications.

Findings

Goldstini have a universal mass twice the gravitino mass.

Visible sector fields can couple predominantly to goldstini, changing decay modes.

Novel collider signatures include displaced vertices and gravitino-less spectra.

Abstract

Supersymmetric phenomenology has been largely bound to the hypothesis that supersymmetry breaking originates from a single source. In this paper, we relax this underlying assumption and consider a multiplicity of sectors which independently break supersymmetry, thus yielding a corresponding multiplicity of goldstini. While one linear combination of goldstini is eaten via the super-Higgs mechanism, the orthogonal combinations remain in the spectrum as physical degrees of freedom. Interestingly, supergravity effects induce a universal tree-level mass for the goldstini which is exactly twice the gravitino mass. Since visible sector fields can couple dominantly to the goldstini rather than the gravitino, this framework allows for substantial departures from conventional supersymmetric phenomenology. In fact, this even occurs when a conventional mediation scheme is augmented by additional supersymmetry breaking sectors which are fully sequestered. We discuss a number of striking collider signatures, including various novel decay modes for the lightest observable-sector supersymmetric particle, gravitinoless gauge-mediated spectra, and events with multiple displaced vertices. We also describe goldstini cosmology and the possibility of goldstini dark matter.