Search for neutral Higgs bosons in events with multiple bottom quarks at the Tevatron

The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with $b$ quarks is reported. The data, corresponding to $2.6{\mathrm{fb}}^{-1}$ of integrated luminosity at CDF and $5.2{\mathrm{fb}}^{-1}$ at D0, have been collected in final states containing three or more $b$ jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example, in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode.

Figure 1

Model-independent 95% C.L. upper limits on the product of cross section and branching ratio for the combined analyses, assuming a Higgs boson width significantly smaller than the experimental resolution. The dark and light shaded regions correspond to the one and 2 standard deviation bands around the median expected limit.

Figure 2

95% C.L. lower limit in the $(M_A,\tan \beta )$ plane for the $m_h^{\max }$, $\mu =-200\mathrm{GeV}$, including Higgs boson width effects and using the fact that for the $\tan \beta$ range considered, either $h$ and $A$, or $H$ and $A$ (depending on $M_A$) are effectively mass degenerate. The exclusion limit obtained from the LEP experiments is also shown.