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Compact Muon Solenoid
LHC, CERN

CMS-PAS-SMP-19-004
Measurement of the associated production of a Z boson with charm or bottom quark jets in proton-proton collisions at $\sqrt{s}= $ 13 TeV
Abstract: Ratios of cross sections, $\sigma$(Z + c jets)/$\sigma$(Z + jets), $\sigma$(Z + b jets)/$\sigma$(Z + jets), and $\sigma$(Z + c jets)/$\sigma$(Z + b jets) in the associated production of a Z boson with at least one charm or bottom quark jet are measured in pp collisions at $\sqrt{s}= $ 13 TeV using 35.9 fb$^{-1}$ of data collected by the CMS experiment at the CERN LHC. The fiducial volume of the measurement is defined by jet transverse momentum $p_{\mathrm{T}} > $ 30 GeV and pseudorapidity $|{\eta}| < $ 2.4. The Z bosons are selected within the mass range of 71 and 111 GeV requiring leptons (electrons or muons) with $p_{\mathrm{T}} > $ 25 GeV and $|{\eta}| < $ 2.4. Results on the inclusive and differential cross section ratios as functions of jet and Z boson transverse momentum are compared with predictions from leading and next-to-leading order perturbative QCD calculations. These are the first of a kind measurements at 13 TeV, and the measurement precision exceeds that of the current theoretical predictions.
CMS Publications
Compact Muon Solenoid
LHC, CERN