Studying Gaugino Mass Unification at the LHC

TL;DR

This paper develops a systematic, model-independent approach to detect deviations from gaugino mass unification at the LHC, focusing on the mirage pattern, and demonstrates that non-universality can be identified with high confidence in most supersymmetric models.

Contribution

It introduces an analytic metric on signature space to detect gaugino mass non-universality without reconstructing individual masses, improving previous methods.

Findings

80% of parameter space detectable at 10% non-universality level

Method effective with about 10 fb^{-1} of data

Framework adaptable to realistic LHC conditions

Abstract

We begin a systematic study of how gaugino mass unification can be probed at the CERN Large Hadron Collider (LHC) in a quasi-model independent manner. As a first step in that direction we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. We improve on previous methods to define an analytic expression for the metric on signature space and use it to study one-parameter deviations from universality in the gaugino sector, randomizing over other soft supersymmetry-breaking parameters. We put forward three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with an integrated luminosity of order 10 inverse femptobarns. We discuss strategies for improving the method and for adding more realism in dealing with the actual experimental circumstances of the LHC.