Supersymmetry without Supersymmetry

TL;DR

This paper explores the idea that supersymmetry might not be fundamental but could emerge as an approximate symmetry at low energies through specific high-energy scenarios, potentially solving hierarchy and cosmological problems.

Contribution

It proposes novel mechanisms where supersymmetry is not fundamental but emergent, avoiding typical supersymmetry breaking issues and linking to extra-dimensional theories via AdS/CFT.

Findings

Supersymmetry can emerge as an accidental symmetry at low energies.

The framework eliminates the need for gravitinos and moduli, addressing cosmological issues.

Supersymmetry breaking can occur without fine-tuning or small parameters.

Abstract

We investigate the possibility that supersymmetry is not a fundamental symmetry of nature, but emerges as an accidental approximate global symmetry at low energies. This can occur if the visible sector is non-supersymmetric at high scales, but flows toward a strongly-coupled superconformal fixed point at low energies; or, alternatively, if the visible sector is localized near the infrared brane of a warped higher-dimensional spacetime with supersymmetry broken only on the UV brane. These two scenarios are related by the AdS/CFT correspondence. In order for supersymmetry to solve the hierarchy problem, the conformal symmetry must be broken below 10^{11} GeV. Accelerated unification can naturally explain the observed gauge coupling unification by physics below the conformal breaking scale. In this framework, there is no gravitino and no reason for the existence of gravitational moduli, thus eliminating the cosmological problems associated with these particles. No special dynamics is required to break supersymmetry; rather, supersymmetry is broken at observable energies because the fixed point is never reached. In 4D language, this can be due to irrelevant supersymmetry breaking operators with approximately equal dimensions. In 5D language, the size of the extra dimension is stabilized by massive bulk fields. No small input parameters are required to generate a large hierarchy. Supersymmetry can be broken in the visible sector either through direct mediation or by the F term of the modulus associated with the breaking of conformal invariance.