Low Fine Tuning in Yukawa-deflected Gauge Mediation

TL;DR

This paper explores gauge-mediated supersymmetry breaking models with non-unified messengers and matter-messenger couplings, achieving low fine-tuning by modifying gaugino mass ratios and soft mass contributions, with implications for collider searches.

Contribution

It introduces models with non-unified messengers and matter-messenger couplings that reduce fine-tuning and enhance Higgs mass without heavy stops, providing testable collider predictions.

Findings

Some models are already excluded by LHC searches.

Scenarios with less than 2% tuning are testable at the ILC.

The models achieve a balance between Higgs mass, fine-tuning, and collider constraints.

Abstract

We discuss a class of models with gauge-mediated supersymmetry breaking characterized by a non-unified messenger sector inducing non-standard gaugino mass ratios, as well as by additional contributions to the soft mass terms from a matter-messenger coupling. The well-known effect of this coupling is to generate A-terms at one-loop level, hence raising the Higgs mass without relying on super-heavy stops. At the same time, a hierarchy between Wino and gluino masses, as induced by the non-unified messenger fields, can greatly lower the radiative corrections to the Higgs soft mass term driven by the high-energy parameters, thus reducing the fine tuning. We search for models with low fine tuning within this scenario, and we discuss the spectrum, collider phenomenology, constraints, and prospects of the found solutions. We find that some setups are accessible or already excluded by searches at the Large Hadron Collider, and all our scenarios with a tuning better than about 2\% can be tested at the International Linear Collider.