Energy calibration of b-quark jets with Z→bb¯ decays at the Tevatron collider

The energy measurement of jets produced by b-quarks at hadron colliders suffers from biases due to the peculiarities of the hadronization and decay of the originating B hadron. The impact of these effects can be estimated by reconstructing the mass of Z boson decays into pairs of b-quark jets. From a sample of 584pb-1 of data collected by the CDF experiment in 1.96 TeV proton–antiproton collisions at the Tevatron collider, we show how the Z signal can be identified and measured. Using the reconstructed mass of Z candidates we determine the energy calibration of b-quark jets with a precision better than 2%. This measurement allows a reduction of one of the dominant source of uncertainty in analyses based on high-transverse momentum b-quark jets. We also determine, as a cross-check of our analysis, the Z boson cross-section in hadronic collisions using the bb¯ final state as σZ×B(Z→bb¯)=1.58-0.41+0.64nb.