Who's Afraid of the Supersymmetric Dark? The Standard Model vs Low-Energy Supergravity

TL;DR

This paper investigates the stability of supergravity-based scalar potentials against quantum effects from heavy particles, proposing a model where supersymmetry persists in gravity but not in the visible sector, with implications for dark matter.

Contribution

It provides evidence that supergravity form remains stable under quantum corrections from heavy particles, supporting a low-energy supersymmetry scenario with a non-linearly realized visible sector.

Findings

Supergravity form is stable against integrating out heavy particles.

A model with supersymmetry in gravity but not in the visible sector is proposed.

The model predicts distinctive features in Higgs couplings and dark-sector physics.

Abstract

Use of supergravity equations in astronomy and late-universe cosmology is often criticized on three grounds: (i) phenomenological success usually depends on the supergravity form for the scalar potential applying at the relevant energies; (ii) the low-energy scalar potential is extremely sensitive to quantum effects involving very massive particles and so is rarely well-approximated by classical calculations of its form; and (iii) almost all Standard Model particles count as massive for these purposes and none of these are supersymmetric. Why should Standard Model loops preserve the low-energy supergravity form even if supersymmetry is valid at energies well above the electroweak scale? We use recently developed tools for coupling supergravity to non-supersymmetric matter to estimate the loop effects of heavy non-supersymmetric particles on the low-energy effective action, and provide evidence that the supergravity form is stable against integrating out such particles (and so argues against the above objection). This suggests an intrinsically supersymmetric picture of Nature where supersymmetry survives to low energies within the gravity sector but not the visible sector (for which supersymmetry is instead non-linearly realized). We explore the couplings of both sectors in this picture and find that the presence of auxiliary fields in the gravity sector makes the visible sector share many features usually attributed to linearly realized supersymmetry although (unlike for the MSSM) a second Higgs doublet is not required for all Yukawa couplings to be non-vanishing and changes the dimension of the operator generating the Higgs mass. We discuss the naturalness of this picture and some of the implications it might have when searching for dark-sector physics.