High-Precision Predictions for the Light $CP$-Even Higgs Boson Mass of the Minimal Supersymmetric Standard Model

For the interpretation of the signal discovered in the Higgs searches at the LHC it will be crucial in particular to discriminate between the minimal Higgs sector realized in the standard model (SM) and its most commonly studied extension, the minimal supersymmetric standard model (MSSM). The measured mass value, having already reached the level of a precision observable with an experimental accuracy of about 500 MeV, plays an important role in this context. In the MSSM the mass of the light $CP$-even Higgs boson, $M_h$, can directly be predicted from the other parameters of the model. The accuracy of this prediction should at least match the one of the experimental result. The relatively high mass value of about 126 GeV has led to many investigations where the scalar top quarks are in the multi-TeV range. We improve the prediction for $M_h$ in the MSSM by combining the existing fixed-order result, comprising the full one-loop and leading and subleading two-loop corrections, with a resummation of the leading and subleading logarithmic contributions from the scalar top sector to all orders. In this way for the first time a high-precision prediction for the mass of the light $CP$-even Higgs boson in the MSSM is possible all the way up to the multi-TeV region of the relevant supersymmetric particles. The results are included in the code FeynHiggs.

Figure 1

Upper plot: $M_h$ as a function of $M_S$ for $X_t=0$ (solid) and $X_t/M_S=2$ (dashed). The full result (“$\mathrm{LL}+\mathrm{NLL}$”) is compared with results containing the logarithmic contributions up to the three-loop,$\dots$, seven-loop level and with the fixed-order FD result (“FH295”). Lower plot: comparison of FeynHiggs (red) with H3m (blue). In green we show the FeynHiggs three-loop result at $\mathcal{O}({\alpha }_t{\alpha }_s^2)$ (full) as dashed (solid) line.