Jet multiplicity and differential production cross sections of Z+jets events in proton-proton collisions at 7 TeV

In this paper a measurement of differential cross sections for the $Z$ boson production in association with jets in proton-proton collisions with a center-of-mass energy $\sqrt{s} = 7$~TeV is presented. The full dataset recorded by CMS in 2011, which corresponds to a total integrated luminosity of 4.9~fb$^{-1}$, has been used. $Z$ boson candidates in the dielectron and dimuon final states have been selected. The differential jet rate cross section is measured, as well as the transverse momentum and pseudorapidity distributions for the four highest transverse momentum jets. The distribution of the scalar sum of jet transverse momenta is also measured as a function of the jet multiplicity. All distributions are presented after deconvoluting the detector effects. Several Monte-Carlo predictions at leading and next-to-leading order in QCD are compared with the experimental measurements.