Search for the Wh Production Using High-pT Isolated Like-Sign Dilepton Events in Run-II with 1.9 /fb

Abstract

We search for the neutral higgs production associated with the $W$ boson using high-$p_{T}$ isolated like-sign dilepton events in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV. The data were collected with the CDF-II detector at the Fermilab Tevatron collider and correspond to an integrated luminosity of 1.9 ${\rm fb}^{-1}$. We examine the dilepton events on the plane of the 2nd lepton $p_{T}$ ($p_{T2}$) versus the $ p_{T}$ of dilepton system ($p_{T12}$) and tune the final cut to maximize the sensitivity on the plane. We set the final cut to the 2nd lepton $p_{T}$ greater than 20 GeV/c and the $p_{T}$ of dilepton system greater than 15 GeV/c. The expected number of signal events is 0.46 for the fermiophobic higgs of the mass 110 GeV/$c^{2}$ and 0.19 for the mass 160 GeV/$c^{2}$ assuming the Standard Model cross section. The number of events for the Standard Model higgs is 0.02 and 0.18 for 110 GeV/$c^2$ and 160 GeV/$c^{2}$, respectively. The expected number of backgrounds is 3.23 $\pm$ 0.69, while we observed 3 events in the data. From these results, we obtain the limits on $\sigma(p\bar{p}\to Wh) \times Br(h\to W^{+}W^{-})$ of 2.2 pb for the higgs of 110 GeV/$c^{2}$ and 1.4 pb for 160 GeV/$c^2$ at the 95% confidence level.