Precise Prediction for the Mass of the Lightest Higgs Boson in the MSSM

Abstract

The leading diagrammatic two-loop corrections are incorporated into the prediction for the mass of the lightest Higgs boson, $\mh$, in the Minimal Supersymmetric Standard Model (MSSM). The results, containing the complete diagrammatic one-loop corrections, the new two-loop result and refinement terms incorporating leading electroweak two-loop and higher-order QCD contributions, are discussed and compared with results obtained by renormalization group calculations. Good agreement is found in the case of vanishing mixing in the scalar quark sector, while sizable deviations occur if squark mixing is taken into account.

Figures (5)

• Figure 1: One- and two-loop results for $m_h$ as a function of $M_{t}^{LR}/m_{\tilde{q}}$ for two values of $\tan \beta\space$. The two steps of refinement discussed in the text are shown separately.
• Figure 2: The mass of the lightest Higgs boson for $\tan \beta\space = 1.6$ and $\tan \beta\space = 40$. The tree-level, the one-loop and the two-loop results for $m_h$ are shown as a function of $m_{\tilde{q}}$ for the no-mixing and the maximal-mixing case.
• Figure 3: Comparison between the Feynman-diagrammatic calculations and the results obtained by renormalization group methods mhiggsRG1b. The mass of the lightest Higgs boson is shown for the two scenarios with $\tan \beta\space = 1.6$ and $\tan \beta\space = 40$ for the case of vanishing mixing in the $\tilde{t}$-sector.
• Figure 4: Comparison between the Feynman-diagrammatic calculations and the results obtained by renormalization group methods mhiggsRG1b. The mass of the lightest Higgs boson is shown for the two scenarios with $\tan \beta\space = 1.6$ and $\tan \beta\space = 40$ for increasing mixing in the $\tilde{t}$-sector and $m_{\tilde{q}} = M_A$.
• Figure 5: Comparison between the Feynman-diagrammatic calculations and the results obtained by renormalization group methods mhiggsRG1b. The mass of the lightest Higgs boson is shown for the two scenarios with $\tan \beta\space = 1.6$ and $\tan \beta\space = 40$ as a function of the heavier physical $\tilde{t}$ mass $m_{\tilde{t}_2}$. For the curves with $\theta_{\tilde{t}} = 0$ a mass difference $\Delta m_{\tilde{t}} = 0 \,\, {\mathrm GeV}$ is assumed whereas for $\theta_{\tilde{t}} = -\pi/4$ we chose $\Delta m_{\tilde{t}} = 350 \,\, {\mathrm GeV}$, for which the maximal Higgs masses are achieved.