Measurement of Associated Production of Z Bosons with Charm Quark Jets in pp¯ Collisions at s√=1.96 TeV

Abstract

We present the first measurements of the ratios of cross sections σ(pp¯→Z+c jet)/σ(pp¯→Z+jet) and σ(pp¯→Z+c jet)/σ(pp¯→Z+b jet) for the associated production of a Z boson with at least one charm or bottom quark jet. Jets have transverse momentum ​pjetT​>20 GeV and pseudorapidity |​ηjet​|<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 pp¯ collisions collected with the D0 detector at the Fermilab Tevatron Collider at s√=1.96 TeV. The measurements show significant deviations from perturbative QCD calculations and predictions from various event generators.