Kinetically-Enhanced Anomaly Mediation

TL;DR

This paper proposes a modification to anomaly-mediated supersymmetry breaking involving an exotic U(1)_x gauge sector, which addresses the tachyonic slepton problem and predicts a distinctive, viable superpartner spectrum with potential LHC signatures.

Contribution

It introduces a new U(1)_x gauge sector coupled via kinetic mixing to the MSSM, providing a novel solution to tachyonic slepton issues in AMSB models.

Findings

The model yields a flavor-universal, viable MSSM spectrum.

It predicts distinctive superpartner signatures at the LHC.

The scenario can be phenomenologically consistent and testable.

Abstract

We investigate a modification of anomaly-mediated supersymmetry breaking (AMSB) with an exotic U(1)_x gauge sector that can solve the tachyonic slepton problem of minimal AMSB scenarios. The new U(1)_x multiplet is assumed to couple directly to the source of supersymmetry breaking, but only indirectly to the minimal supersymmetric Standard Model (MSSM) through kinetic mixing with hypercharge. If the MSSM sector is also sequestered from the source of supersymmetry breaking, the contributions to the MSSM soft terms come from both AMSB and the U(1)_x kinetic coupling. We find that this arrangement can give rise to a flavour-universal, phenomenologically viable, and distinctive spectrum of MSSM superpartners. We also investigate the prospects for discovery and the most likely signatures of this scenario at the Large Hadron Collider (LHC).