Azimuthal correlations in Z+jets events in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The production of Z bosons associated with jets
is measured in pp collisions at √s = 13 TeV with data
recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3 fb−1. The multiplicity
of jets with transverse momentum pT > 30 GeV is measured for different regions of the Z boson’s pT(Z ), from
lower than 10 GeV to higher than 100 GeV. The azimuthal
correlation Δφ between the Z boson and the leading jet, as
well as the correlations between the two leading jets are
measured in three regions of pT(Z ). The measurements are
compared with several predictions at leading and next-toleading orders, interfaced with parton showers. Predictions
based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton
interactions and higher jet multiplicities are not important.
The effects of multiple parton interactions are shown to be
important to correctly describe the measured spectra in the
low pT(Z ) regions.