Energy Calibration of b-Quark Jets with Z->b-bbar Decays at the Tevatron Collider

TL;DR

This paper presents a method to calibrate b-quark jet energies at the Tevatron by reconstructing Z->b-bbar decays, achieving a precision better than 2%, which reduces uncertainties in high-energy physics analyses.

Contribution

The study introduces a novel calibration technique using Z boson decays into b-quark pairs to improve jet energy measurements at hadron colliders.

Findings

Jet energy scale factor for b-quark jets determined with <2% precision.

Z boson cross section in b-bbar final state measured as 1578 +636 -410 pb.

Method reduces dominant uncertainties in b-jet analyses.

Abstract

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 584 pb-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 a jet energy scale factor for 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 b-bbar final state as sigma x B(Z->b-bbar) = 1578 +636 -410 pb.