Mixed modulus and anomaly mediation in light of the muon g − 2 anomaly

The new measurement of the anomalous magnetic moment of muon at the Fermilab Muon g− 2 experiment has strengthened the significance of the discrepancy between the standard model prediction and the experimental observation from the BNL measurement. If new physics responsible for the muon g− 2 anomaly is supersymmetric, one should consider how to obtain light electroweakinos and sleptons in a systematic way. The gauge coupling unification allows a robust prediction of the gaugino masses, indicating that the electroweakinos can be much lighter than the gluino if anomaly-mediated supersymmetry breaking is sizable. As naturally leading to mixed modulus-anomaly mediation, the KKLT scenario is of particular interest and is found capable of explaining the muon g− 2 anomaly in the parameter region where the lightest ordinary supersymmetric particle is a bino-like neutralino or slepton.

Muon g − 2 anomaly in anomaly mediation

The long-standing muon g − 2 anomaly has been confirmed recently at the Fermilab. The combined discrepancy from Fermilab and Brookhaven results shows a difference from the theory at a significance of 4.2 σ. In addition, the LHC has updated the lower mass bound of a pure wino. In this letter, we study to what extent the g − 2 can be explained in anomaly mediation scenarios, where the pure wino is the dominant dark matter component. To this end, we derive some model-independent constraints on the particle spectra and g − 2. We find that the g − 2 explanation at the 1σ level is driven into a corner if the higgsino threshold correction is suppressed. On the contrary, if the threshold correction is sizable, the g − 2 can be explained. In the whole viable parameter region, the gluino mass is at most 2 − 4 TeV, the bino mass is at most 2 TeV, and the wino dark matter mass is at most 1 − 2 TeV. If the muon g − 2 anomaly is explained in the anomaly mediation scenarios, colliders and indirect search for the dark matter may find further pieces of evidence in the near future. Possible UV models for the large threshold corrections are discussed.

Hybrid anomaly and gravity mediation for electroweak supersymmetry

In this paper, we propose a hybrid mediation and hybrid supersymmetry breaking. In particular, the RG-invariant anomaly mediation is considered. Together with additional gravity mediation, the slepton tachyon problem of anomaly mediation is solved automatically. The special properties are that all color sparticles masses fall into several TeV regions due to the large [Formula: see text] and [Formula: see text] which are well beyond the scope of current LHC Run II limits. Unlike the gauge mediation, the dark matter candidate is still the lightest neutralino and the correct dark matter relic density can be realized within the framework of mixed axion-Wino dark matter. Due to the existence of multi-component axion-Wino dark matter, the direct detection cross-section is suppressed to evade the tightest LUX, PandaX bound.