Study of Z+jet correlations in PbPb and pp collisions at $\sqrt{s_{\rm NN}} = 5.02~\mathrm{TeV}$

The production of Z+jet pairs is measured for the first time in pp and central PbPb collisions at a centre-of-mass energy of 5.02 TeV per nucleon pair, using data samples collected by the CMS experiment at the LHC. The Z+jet azimuthal angle correlations and $p_T$ imbalance are analysed for events containing a Z boson with transverse momentum $p_\mathrm{T}^\mathrm{Z} > 60~\mathrm{GeV}/c$ and an associated jet with $p_\mathrm{T}^\mathrm{Jet} > 30~\mathrm{GeV}/c$. A moderate shift in the $p_\mathrm{T}^\mathrm{Jet}/p_\mathrm{T}^\mathrm{Z}$ ratio is seen in central PbPb collisions with respect to the ratio found using pp data.