Search for Standard Model Higgs Boson Production
in Association with a W Boson with 2.7 fb-1 of CDF Data

 




Introduction:

We present a search for Standard Model Higgs Boson production in association with a W boson using 2.7 fb-1 of CDF data. We select events with a high-pT lepton, a neutrino, and two jets. At least one of the jets must be identified as a b-quark jet (tagged). We optimized two multivariate discriminants designed to separate signal from background. One discriminant uses complementary Matrix Element and Boosted Decision Tree techniques. The other uses Neural Networks. We perform binned likelihood fits of the discriminants and set 95% confidence level upper limits on the WH production cross section times branching ratio as a function of Higgs mass for each analysis technique. In order to improve sensitivity, the multivariate outputs of both analyses are then combined into a super-discriminant by using a neural network. This combination results in about a 15% improvement over the previous blessed results from either individual analysis.




Main Analysis Web Pages:





Results -- Limits:

  • Expected and observed upper limit cross sections in SM units for different Higgs mass points using ME+BDT:

    • mH (GeV) Expected (&sigma/SM) Observed (&sigma/SM)
    100 3.80 3.34
    105 3.98 3.56
    110 4.53 5.77
    115 5.24 6.23
    120 6.34 7.08
    125 7.97 8.37
    130 9.97 11.8
    135 13.4 17.1
    140 19.2 18.4
    145 27.0 44.0
    150 48.7 84.1

  • Expected and observed upper limit cross sections in SM units for different Higgs mass points using NN:

    • mH (GeV) Expected (&sigma/SM) Observed (&sigma/SM)
    100 4.3 3.6
    105 4.6 3.6
    110 5.0 3.7
    115 5.8 5.2
    120 6.9 5.6
    125 8.2 8.2
    130 10.0 8.9
    135 13.8 12.4
    140 19.4 23.1
    145 28.9 30.6
    150 43.2 61.1






Combined Results



  • Expected and observed upper limit cross sections in SM units for different Higgs mass:

    • mH (GeV) Expected (&sigma/SM) Observed (&sigma/SM)
    100 3.5 3.3
    105 3.8 3.6
    110 4.1 4.9
    115 4.8 5.6
    120 5.9 5.9
    125 7.2 8.0
    130 8.7 8.9
    135 12.2 13.2
    140 17.5 26.5
    145 25.6 42.1
    150 40.5 75.5






Public Notes: