Evidence for WZ and ZZ production in final states with b-tagged jets

Abstract

We present evidence for the combined production of VZ (V=W or Z) events in final states containing charged leptons (electrons or muons) or neutrinos, and heavy flavor jets, using data collected by the DO detector at the Fermilab Tevatron Collider. The analyzed samples correspond to 7.5 to 8.4/fb of ppbar collisions at sqrt s = 1.96 TeV. Assuming the ratio of the production cross sections sigma(WZ) and sigma(ZZ) as predicted by the standard model, we measure the total VZ cross section to be sigma(VZ) = 5.0 +- 1.0 (stat) +1.3 -1.2 (syst) pb. This corresponds to a significance of 3.3 standard deviations above the background only hypothesis. Furthermore, we have separately measured the cross sections for the WZ and ZZ processes to be simga(WZ) = 5.9 +- 1.4 (stat) +- 0.7 (syst) pb and sigma(ZZ) = 0.45 +- 0.61 (stat) +- 1.2 (syst) pb, in agreement with the standard model prediction.