Anomalous muon magnetic moment, supersymmetry, naturalness, LHC search limits and the landscape

摘要

The recent measurement of the muon anomalous magnetic momentaμ≡(g?2)μ/2by the Fermilab Muong?2experiment sharpens an earlier discrepancy between theory and the BNL E821 experiment. We examine the predictedΔaμ≡aμ(exp)?aμ(th)in the context of supersymmetry with low electroweak naturalness (restricting to models which give a plausible explanation for the magnitude of the weak scale). A global analysis including LHC Higgs mass and sparticle search limits points to interpretation within the normal scalar mass hierarchy (NSMH) SUSY model wherein first/second generation matter scalars are much lighter than third generation scalars. We present a benchmark model for a viable NSMH point which is natural, obeys LHC Higgs and sparticle mass constraints and explains the muon magnetic anomaly. Aside from NSMH models, then we find the(g?2)μanomaly cannot be explained within the context of natural SUSY, where a variety of data point to decoupled first/second generation scalars. The situation is worse within the string landscape where first/second generation matter scalars are pulled to values in the10?50TeV range. An alternative interpretation for SUSY models with decoupled scalar masses is that perhaps the recent lattice evaluation of the hadronic vacuum polarization could be confirmed which leads to a Standard Model theory-experiment agreement in which case there is no anomaly.