Measurement of the ratio of inclusive cross sections $\sigma (p\bar{p} \rightarrow Z+2~b \text{jets}) / \sigma (p\bar{p} \rightarrow Z+ \text{2 jets})$ in $p\bar{p}$ collisions at $\sqrt s=1.96$ TeV

TL;DR

This paper reports a measurement of the ratio of cross sections for Z boson production with two b-jets versus two jets in proton-antiproton collisions at 1.96 TeV, confirming QCD predictions.

Contribution

First precise measurement of the ratio of Z+2b jets to Z+2 jets cross sections at Tevatron energies, validating perturbative QCD models.

Findings

Measured ratio: 0.0236 ± 0.0032 (stat) ± 0.0035 (syst)

Results agree with NLO QCD and Monte Carlo predictions

Provides important data for background estimation in Higgs searches

Abstract

We measure the ratio of cross sections, $\sigma(p\bar{p}\rightarrow Z+2~b~\text{jets})$/$\sigma(p\bar{p}\rightarrow Z+\text{2 jets})$, for associated production of a $Z$ boson with at least two jets with transverse momentum $p_T^{\rm jet} > 20$ GeV and pseudorapidity $|\eta^{\rm jet}| < 2.5$. This measurement uses data corresponding to an integrated luminosity of 9.7 fb$^{-1}$ collected by the \DO experiment in Run II of Fermilab's Tevatron \ppbar Collider at a center-of-mass energy of 1.96 TeV. The measured integrated ratio of $0.0236\pm0.0032\left(\mbox{stat}\right)\pm0.0035\left(\mbox{syst}\right)$ is in agreement with predictions from next-to-leading-order perturbative QCD and the Monte Carlo event generators {\sc pythia} and {\sc alpgen}.