Search for a Higgs Boson Decaying to Two $W$ Bosons at CDF

We present a search for a Higgs boson decaying to two $W$ bosons in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ center-of-mass energy. The data sample corresponds to an integrated luminosity of $3.0{\mathrm{fb}}^{-1}$ collected with the CDF II detector. We find no evidence for production of a Higgs boson with mass between 110 and $200\mathrm{GeV}/c^2$, and determine upper limits on the production cross section. For the mass of $160\mathrm{GeV}/c^2$, where the analysis is most sensitive, the observed (expected) limit is 0.7 pb (0.9 pb) at 95% Bayesian credibility level which is 1.7 (2.2) times the standard model cross section.

Figure 1

The likelihood ratio distribution from (a) the ME discriminate alone and (b) the full NN score for $m_H=160\mathrm{GeV}/c^2$. The Higgs boson distribution is normalized to the SM expectation. The distributions are shown only for the high $S/B$ class, which provides the majority of the sensitivity.

Figure 2

Upper limits on $(\sigma \times \mathcal{B})/(\sigma \times \mathcal{B}{)}_{\mathrm{SM}}$ versus $m_H$.