125 GeV Higgs boson mass and muon $g-2$ in 5D MSSM

In the minimal supersymmetric standard model (MSSM), the tension between the observed Higgs boson mass and the experimental result of the muon $g-2$ measurement requires a large mass splitting between stops and smuons/charginos/neutralinos. We consider a five-dimensional (5D) framework of the MSSM with the Randall-Sundrum warped background metric, and show that such a mass hierarchy is naturally achieved in terms of geometry. In our setup, the supersymmetry is broken at the ultraviolet (UV) brane, while all the MSSM multiplets reside in the 5D bulk. An appropriate choice of the bulk mass parameters for the MSSM matter multiplets can naturally realize the sparticle mass hierarchy desired to resolve the tension. The gravitino is localized at the UV brane and hence becomes very heavy, while the gauginos spreading over the bulk acquire their masses suppressed by the fifth dimensional volume. As a result, the lightest sparticle neutralino is a candidate for the dark matter as usual in the MSSM. In addition to reproducing the SM-like Higgs boson mass of around 125 GeV and the measured value of the muon $g-2$, we consider a variety of phenomenological constraints, and present the benchmark particle mass spectra that can be explored at the LHC Run-2 in the near future.

Figure 1

Behavior of the geometrical coefficient as a function of the bulk mass parameter: ${\mathcal{C}}_{\mathrm{\Phi }}=\sqrt{\frac{(1-2c_{\mathrm{\Phi }})}{2({\omega }^{(-1+2c_{\mathrm{\Phi }})}-1)}}$. The plot is a demonstration for the case with $\omega ={10}^{-12}$.