Measurement of associated production of Z bosons with charm quark jets in ppbar collisions at sqrt(s)=1.96 TeV

TL;DR

This paper reports the first measurements of cross section ratios for Z boson production with charm versus bottom jets in proton-antiproton collisions, revealing deviations from theoretical predictions.

Contribution

It provides the first experimental measurements of Z+c jet to Z+jet and Z+c jet to Z+b jet cross section ratios at Tevatron energies, highlighting discrepancies with QCD models.

Findings

Measured cross section ratios as functions of jet and Z boson transverse momenta.

Observed significant deviations from perturbative QCD calculations.

Provided differential measurements using 9.7 fb^{-1} of data.

Abstract

We present the first measurements of the ratios of cross sections, \sigma(ppbar -> Z+c jet)/\sigma(ppbar -> Z+jet) and \sigma(ppbar -> Z+c jet)/\sigma(ppbar -> Z+b jet) for the associated production of a Z boson with at least one charm or bottom quark jet. Jets have transverse momentum p_{T}>20 GeV and pseudorapidity |\eta|<2.5. These cross section ratios are measured differentially as a function of jet and $Z$ boson transverse momenta, based on 9.7 fb^{-1} of ppbar collisions collected with the D0 detector at the Fermilab Tevatron Collider at sqrt(s) = 1.96 TeV. The measurements show significant deviations from perturbative QCD calculations and predictions from various event generators.