No-go for tree-level R-symmetry breaking

Feihu Liu,Zheng Sun,Muyang Liu

doi:10.1140/epjc/s10052-017-5327-2

Abstract

We show that in gauge mediation models with tree-level R-symmetry breaking where supersymmetry and R-symmetries are broken by different fields, the gaugino mass either vanishes at one loop or finds a contribution from loop-level R-symmetry breaking. Thus tree-level R-symmetry breaking for phenomenology is either no-go or redundant in the simplest type of models. Including explicit messenger mass terms in the superpotential with a particular R-charge arrangement is helpful to bypass the no-go theorem, and the resulting gaugino mass is suppressed by the messenger mass scale.

Highlights

Supersymmetry (SUSY) [1,2] provides a natural solution to several unsolved problems in the Standard Model (SM), such as the gauge hierarchy problem, gauge coupling unification and dark matter candidates
To avoid light sparticles in the supersymmetric standard model (SSM), SUSY must be broken in a hidden sector, and the SUSY breaking effects are mediated to the observable SSM sector by a messenger sector, giving sparticle mass spectrum and coupling constants which may be examined at the LHC or other future experiments
SUSY breaking fields are coupled to messengers which are charged under the SM gauge symmetry

Summary

Introduction

Supersymmetry (SUSY) [1,2] provides a natural solution to several unsolved problems in the Standard Model (SM), such as the gauge hierarchy problem, gauge coupling unification and dark matter candidates. SUSY breaking fields are coupled to messengers which are charged under the SM gauge symmetry. SUSY breaking is mediated to the SSM sector through gauge interactions, and soft terms such as the gaugino mass emerge at low energy. For loop-level R-symmetry breaking, the SUSY breaking spurion field X breaks the R-symmetry at loop level. A tree-level R-symmetry breaking model has at least two spurions which break SUSY and R-symmetry, respectively. Tree-level R-symmetry breaking fails its original motivation to generate the gaugino mass, and we obtain a no-go statement for these models. We are to show that it is possible to bypass the no-go theorem by including explicit messenger mass terms in the superpotential with a particular R-charge arrangement, and the resulting gaugino mass is suppressed by the ratio between the R-symmetry breaking scale and the messenger mass scale

Gaugino masses in ordinary gauge mediation models

No-go with separated SUSY and R-symmetry breaking

Bypassing the no-go theorem with explicit messenger mass terms

Conclusion and outlook