A Search for the Higgs Boson Produced in Association with Z --> ell+ ell- Using the Matrix Element Method at CDF II

We present a search for associated production of the standard model (SM) Higgs boson and a Z boson where the Z boson decays to two leptons and the Higgs decays to a pair of b quarks in p anti-p collisions at the Fermilab Tevatron. We use event probabilities based on SM matrix elements to construct a likelihood function of the Higgs content of the data sample. In a CDF data sample corresponding to an integrated luminosity of 2.7 fb-1 we see no evidence of a Higgs boson with a mass between 100 GeV/c2 and 150 GeV/c2. We set 95% confidence level (C.L.) upper limits on the cross-section for ZH production as a function of the Higgs boson mass m_H; the limit is 8.2 times the SM prediction at m_H =115 GeV/c2.