Gauge Mediation with a small mu term and light squarks

TL;DR

This paper proposes a gauge mediation model with two singlets and low-scale messengers that naturally produces a small mu term and light squarks, achieving a Higgs mass above LEP bounds with minimal tuning.

Contribution

It introduces a novel gauge mediation framework that reduces fine-tuning by producing a small mu term and light squarks while maintaining a stable vacuum and perturbativity up to the GUT scale.

Findings

Small mu term (100-300 GeV) achieved through singlet mixing.

Light squarks in the 330-400 GeV range due to spectrum compression.

Higgs mass exceeds 114.4 GeV with tanbeta ~ 1.5.

Abstract

We consider a solution to the mu problem in the context of Non-Minimal Gauge Mediation with two Singlets and Low-Scale Messengers. This solution reduces tuning associated with the "Little Hierarchy" problem by permitting a naturally small mu term (100-300 GeV) due to small mixing between the Singlets. The smallness of mu also relies crucially on compressing the Gauge Mediated sparticle spectrum resulting in 330-400 GeV squarks. In addition to a small mu term, the theory achieves a Higgs mass > 114.4 GeV through a large Higgs quartic coupling when tanbeta ~ 1.5. The vacua studied are globally stable with all couplings perturbative to the GUT scale. The amount of tuning required to get the correct Electroweak scale is of order 10%, with a similar residual tuning associated with the region of parameter space where the lightest CP-even Higgs mass is above the LEP bound.