Measurement of the ZZ production cross section and search for the standard model Higgs boson in the four lepton final state in p(p)over-bar collisions
Abstract
We present a measurement of Z boson pair production in p (p) over bar collisions at 1.96 TeV with 9.6 to 9.8 fb(-1) of D0 data. We examine the final states eeee, ee mu mu, and mu mu mu mu.
Based on selected data, the measured cross section in the mass region M(Z/gamma*) > 30 GeV is sigma(p (p) over bar -> Z/gamma*Z/gamma*) = 1.26(-0.36)(+0.44)(stat)(-0.15)(+0.17) X (syst) +/- 0.08 (lumi) pb; after correcting for the expected ratio of sigma (p (p) over bar -> Z/gamma*Z/gamma*) to sigma(p (p) over bar -> ZZ), we derive a cross section for p (p) over bar -> ZZ production of 1.05(-0.30)(+0.37)(stat)(-0.12)(0.14)(syst) +/- 0.06 (lumi) pb. This result is combined with a previous result from the ZZ -> l(+)l(-) nu(nu) over bar channel resulting in a combined p (p) over bar -> ZZ cross section measurement of 1.32(-0.25)(+0.29) (stat) +/- 0.12 (syst) +/- 0.04 (lumi) pb.
These measurements are consistent with the standard model expectation of 1.43 +/- 0.10 pb. We extend this analysis to search for the standard model (SM) Higgs boson between 115 and 200 GeV.
At a Higgs boson mass of 125 GeV, we expect to set a limit of 43 times the SM expectation at 95% C.L., and set a limit of 42 times the SM expectation at 95% C.L.