MSSM Higgs Boson Searches at the Tevatron and the LHC: Impact of Different Benchmark Scenarios

TL;DR

This work analyzes how supersymmetric radiative corrections, notably the $\Delta_b$ corrections that depend on the higgsino mass parameter $\mu$ and other SUSY parameters, modify MSSM Higgs production and decay rates, thereby reshaping Tevatron exclusion limits and LHC discovery prospects. Using analytic approximations and public codes (e.g., FeynHiggs, HDECAY, HIGLU), the authors quantify how the bottom Yukawa coupling and related Higgs couplings alter channels like $b\bar b\phi, \phi\to b\bar b$, $\phi\to \tau^+\tau^-$, and $t\bar t\to H^\pm W^\mp$, $H^\pm\to \tau\nu$, across benchmark scenarios. They show that including the dominant SUSY radiative corrections can shift $\tan\beta$ bounds by up to about 30 at the Tevatron and modestly affect the LHC wedge region (up to ~8 in $\tan\beta$) depending on $M_A$ and channel, with additional modifications when heavy Higgs bosons decay into charginos/neutralinos. Based on these findings, the paper proposes extending existing MSSM benchmark scenarios to include several $\mu$ values ($\pm 200$, $\pm 500$, $\pm 1000$ GeV) and adding further scenarios (e.g., small $\alpha_{\rm eff}$, gluophobic) to provide robust guidance for current and future hadron-collider Higgs searches.

Abstract

The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. The current limits from the Tevatron and the prospective sensitivities at the LHC are often interpreted in specific MSSM scenarios. For heavy Higgs boson production and subsequent decay into b \bar b or tau^+ tau^-, the present Tevatron data allow to set limits in the M_A-tan_beta plane for small M_A and large tan_beta values. Similar channels have been explored for the LHC, where the discovery reach extends to higher values of M_A and smaller tan_beta. Searches for MSSM charged Higgs bosons, produced in top decays or in association with top quarks, have also been investigated at the Tevatron and the LHC. We analyze the current Tevatron limits and prospective LHC sensitivities. We discuss how robust they are with respect to variations of the other MSSM parameters and possible improvements of the theoretical predictions for Higgs boson production and decay. It is shown that the inclusion of supersymmetric radiative corrections to the production cross sections and decay widths leads to important modifications of the present limits on the MSSM parameter space. The impact on the region where only the lightest MSSM Higgs boson can be detected at the LHC is also analyzed. We propose to extend the existing benchmark scenarios by including additional values of the higgsino mass parameter mu. This affects only slightly the search channels for a SM-like Higgs boson, while having a major impact on the searches for non-standard MSSM Higgs bosons.

Figures (9)

• Figure 1: Change in the limits obtained from the $b \bar{b} \phi$, $\phi \to b \bar{b}$ channel in the $m_h^{\rm max}$ (left) and no-mixing (right) benchmark scenarios for different values of $\mu$. The value $\mu = -200 \,\, \mathrm{GeV}$ was chosen by the D0 Collaboration in Ref. D0bounds. The other curves indicate the corresponding limits for $\mu = +200, \pm 500, \pm 1000 \,\, \mathrm{GeV}$. The curves for $\mu = +500, +1000\,\, \mathrm{GeV}$ ($\mu = +1000 \,\, \mathrm{GeV}$) do not appear in the left (right) plot for the $m_h^{\rm max}$ (no-mixing) scenario, since for these $\mu$ values there is no $\tan \beta$ exclusion below $\tan \beta = 130$ for any value of $M_A$.
• Figure 2: Variation of the limits obtained from the $b \bar{b} \phi$, $\phi \to b \bar{b}$ channel in the no-mixing scenario for different values of $M_{\mathrm {SUSY}}$ and $\mu$. The left plot shows the results for $M_{\mathrm {SUSY}} = 1000, 2000 \,\, \mathrm{GeV}$ and $\mu = \pm 200 \,\, \mathrm{GeV}$, while in the right plot the results for $M_{\mathrm {SUSY}} = 2000 \,\, \mathrm{GeV}$ and $\mu = \pm 200, \pm 500, \pm 1000 \,\, \mathrm{GeV}$ are given.
• Figure 3: Left: Variation of the limits obtained from the $b \bar{b} \phi$, $\phi \to b \bar{b}$ channel in the constrained-$m_h^{\rm max}$ scenario for different values of $\mu$. Right: Variation of the limits obtained from the $p \bar{p} \to \phi \to \tau^+\tau^-$ channel in the constrained-$m_h^{\rm max}$ scenario for different values of $\mu$.
• Figure 4: Impact of including or omitting the $\Delta_b$ correction in the $g g \to \phi$ production process on the limits obtained from the $p \bar{p} \to \phi$, $\phi \to \tau^+\tau^-$ channel. The results are shown for $\mu = \pm 200 \,\, \mathrm{GeV}$ in the $m_h^{\rm max}$ (left) and no-mixing (right) benchmark scenarios benchmark2.
• Figure 5: Variation of the limits obtained from the $p \bar{p} \to \phi \to \tau^+\tau^-$ channel at the Tevatron in the $m_h^{\rm max}$ (left) and no-mixing (right) benchmark scenarios for different values of $\mu$.