Yukawa coupling and anomalous magnetic moment of the muon: an update for the LHC era

TL;DR

This paper explores how a radiatively generated muon Yukawa coupling in the MSSM relates to the muon's anomalous magnetic moment, predicting smuon masses and implications for LHC detection and electron Yukawa coupling.

Contribution

It provides updated predictions for smuon masses based on the absence of a tree-level muon Yukawa coupling and discusses implications for LHC searches and electron Yukawa coupling.

Findings

Light smuon mass range between 750 GeV and 2700 GeV at 2 sigma

Detection of smuon and bino at LHC implies non-zero muon Yukawa coupling

Light selectron near current search limits could indicate non-zero electron Yukawa coupling

Abstract

We study the interplay between a soft muon Yukawa coupling generated radiatively with the trilinear A-terms of the minimal supersymmetric standard model (MSSM) and the anomalous magnetic moment of the muon. In the absence of a tree-level muon Yukawa coupling the lightest smuon mass is predicted to be in the range between 750 GeV and 2700 GeV at 2 sigma, if the bino mass M_1 is below 1 TeV. Therefore, a detection of a smuon (in conjunction with a sub-TeV bino) at the LHC would directly imply a non-zero muon Yukawa coupling in the MSSM superpotential. Inclusion of slepton flavor mixing could in principle lower the mass of one smuon-like slepton below 750 GeV. However, the experimental bounds on radiative lepton decays instead strengthen the lower mass bound, with larger effects for smaller M_1, We also extend the analysis to the electron case and find that a light selectron close to the current experimental search limit may prove the MSSM electron Yukawa coupling to be non-zero.