  Central lead-lead collisions at the LHC energies may pose a particular
challenge for jet identification as multiple jets are produced per each
collision event. We simulate the jet evolution in central Pb-Pb events at
$\sqrt{s_{\rm NN}} = 2.76$ GeV collision energy with EPOS3 initial state, which
typically contains multiple hard scatterings in each event. Therefore the
partons from different jets have a significant chance to overlap in momentum
space. We find that 30% of the jets with $p_\perp > 50$ GeV, identified by the
standard anti-$k_\perp$ jet finding algorithm with jet cone size R=0.3, contain
`intruder' particles from overlapping generator-level jets. This fraction
increases with increasing beam energy and increasing R. The reconstructed
momentum of the jet differs from that of the modelled jet by the loss due to
jet partons which are outside of the jet cone and by the gain due to intruder
partons. The sum of both may be positive or negative. These intruder partons
particularly affect the radial jet momentum distribution because they
contribute mostly at large angles $\Delta r$ with respect to the jet centre.
The study stresses the importance of the jet overlap effect emerging in central
lead-lead collisions at the LHC energies, while being negligible in peripheral
PbPb or $p$Pb/$pp$ collisions.
