Distinguishing anomaly mediation from gauge mediation with a Wino NLSP

TL;DR

This paper compares anomaly mediation and gauge mediation models in supersymmetry, highlighting their similarities and differences, especially focusing on the Wino NLSP and how to distinguish these models through specific observables and measurements.

Contribution

It demonstrates that generalized gauge-mediated models can mimic anomaly mediation predictions and identifies key observables for distinguishing these supersymmetry breaking mechanisms.

Findings

Models with Wino NLSP can be nearly indistinguishable in gaugino mass predictions.

Ratios of selectron, smuon, and stop masses serve as robust distinguishing criteria.

The sign of the gluino soft mass is a definitive but challenging observable.

Abstract

A striking consequence of supersymmetry breaking communicated purely via the superconformal anomaly is that the gaugino masses are proportional to the gauge beta functions. This result, however, is not unique to anomaly mediation. We present examples of ``generalized'' gauge-mediated models with messengers in standard model representations that give nearly identical predictions for the gaugino masses, but positive (mass)^2 for all sleptons. There are remarkable similarities between an anomaly-mediated model with a small additional universal mass added to all scalars and the gauge-mediated models with a long-lived Wino next-to-lightest supersymmetric particle (NLSP), leading to only a small set of observables that provide robust distinguishing criteria. These include ratios of the heaviest to lightest selectrons, smuons, and stops. The sign of the gluino soft mass an unambiguous distinction, but requires measuring a difficult class of one-loop radiative corrections to sparticle interactions. A high precision measurement of the Higgs-b-\bar{b} coupling is probably the most promising interaction from which this sign might be extracted.