Supersymmetric Higgs production at the Large Hadron Collider

TL;DR

This paper surveys the theoretical status of neutral supersymmetric Higgs production at the LHC, emphasizing gluon fusion and bottom-associated production. It demonstrates that heavy-top approximations yield accurate higher-order QCD corrections and that bottom and stop loops can be significant in MSSM, especially at large tanβ. By combining SM NNLO results with an effective Higgs-gluon coupling and resummation of bottom-quark logs, it presents precise inclusive cross sections with reduced scale dependence and discusses the relevance of bbH production. The findings boost the reliability of MSSM Higgs searches and outline remaining challenges to extend precision to a wider set of SUSY parameters.

Abstract

We review the status of theoretical predictions for the production of neutral Higgs bosons at the LHC. Special emphasis is put on the role of bottom quarks in the gluon fusion process and in the associated production of Higgs bosons with bb-bar pairs.

Figures (7)

• Figure 1: Feynman diagrams contributing to gluon fusion: $(a)$$\theta=t,b,\tilde{t},\ldots$ --- $(b)$ two-loop contribution in the .9 MSSM.
• Figure 2: The total cross section at .9 NLO as evaluated in the effective theory (Eq. (\ref{['eq::efft']})), compared to the exact .9 NLO result Spira:1995rrhiglu. Dashed line: only top quarks --- solid line: including bottom quarks ($m_t^{\rm OS} = 175$ GeV, $m_b^{\rm OS} = 5$ GeV).
• Figure 3: Relevance of the exact bottom quark contribution for various values of the bottom Yukawa coupling higlu. $g_b/g_t=1$ corresponds to the Standard Model (see also bill).
• Figure 4: Relative size of the top quark/squark contributions: delta(top,stop)=$\Delta\sigma_{\tilde{t}}/\sigma_t$, see Eq. (\ref{['eq::sigdef']}). Furthermore, $m_t=175$ GeV, and $m_{\tilde{t}R}=m_{\tilde{t}L}\equiv m_{\tilde{t}}$. Solid line: $m_{\tilde{t}}=175$ GeV --- long/middle/short dashes: $m_{\tilde{t}} = 200/300/400$ GeV.
• Figure 5: $K$-factors for the gluon-fusion process. Dashed: Standard Model --- Solid: .9 MSSM (no stop mixing). The narrow (red) band shows the uncertainty due to the missing .9 NNLO contribution in the effective vertex, the wide (green) band is the scale uncertainty (from Ref. Harlander:2003kf).