Probing the Seesaw and Gauge Mediation Scales with BR(\mu\to e\gamma) and |U_{e3}|

TL;DR

This paper discusses how recent experimental bounds on muon to electron gamma decay and measurements of neutrino mixing angles constrain the scales of gauge mediation and the seesaw mechanism in supersymmetry models, with implications for future discoveries.

Contribution

It links experimental bounds on lepton flavor violation and neutrino mixing to the determination of supersymmetry breaking and seesaw scales, highlighting the potential to narrow down these fundamental parameters.

Findings

The MEG bound constrains the gauge mediation scale.

Future observations could determine the mediation scale within one order of magnitude.

The evidence for |U_{e3}| refines predictions of gauge mediated supersymmetry breaking.

Abstract

The new MEG bound on BR(\mu\to e\gamma) provides the strongest upper bound on the scale of gauge mediation of supersymmetry breaking. If, in the future, this decay is observed by MEG, the mediation scale will become known to within one order of magnitude, and the seesaw scale will be constrained. In such a case, contributions from Planck mediated supersymmetry breaking are likely to be non-negligible, and an interpretation in terms of purely seesaw parameters will be impossible. The recent evidence for |U_{e3}|~0.15 further sharpens the predictions of gauge mediated supersymmetry breaking.