  One of the main theoretical systematics in studies of final states with large
jet multiplicities at high-energy hadron colliders is associated with the
merging of QCD parton showers and hard-scattering matrix elements. We present a
method to incorporate the physics of transverse momentum recoils due to
initial-state shower evolution into multi-jet merging algorithms by using the
concept of transverse momentum dependent (TMD) distributions and the associated
parton branching. We investigate the dependence on the merging scale and
illustrate the impact of the new method at the level of both exclusive and
inclusive final-state observables by studying differential jet rates,
transverse momentum spectra and multiplicity distributions, using vector boson
+ jets events at the LHC as a case study.
