https://doi.org/10.1140/epjc/s10052-022-10715-0
Letter
Back-to-back azimuthal correlations in 
jet events at high transverse momentum in the TMD parton branching method at next-to-leading order
1
School of Physics, Peking University, Beijing, China
2
Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
3
Theoretical Physics Department, CERN, Geneva, Switzerland
4
Elementary Particle Physics, University of Antwerp, Antwerp, Belgium
5
University of Oxford, Oxford, UK
6
University of Edinburgh, Edinburgh, UK
7
Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
Received:
7
April
2022
Accepted:
16
August
2022
Published online:
29
August
2022
Azimuthal correlations in jet production at large transverse momenta are computed by matching Parton-Branching (PB) TMD parton distributions and showers with NLO calculations via MCatNLO. The predictions are compared with those for dijet production in the same kinematic range. The azimuthal correlations 
between the Z boson and the leading jet are steeper compared to those in dijet production at transverse momenta 
GeV , while they become similar for very high transverse momenta 
GeV . The different patterns of jet and dijet azimuthal correlations can be used to search for potential factorization-breaking effects in the back-to-back region, which depend on the different color and spin structure of the final states and their interferences with the initial states. In order to investigate these effects experimentally, we propose to measure the ratio of the distributions in for jet- and multijet production at low and at high transverse momenta, and compare the results to predictions obtained assuming factorization. We examine the role of theoretical uncertainties by performing variations of the factorization scale, renormalization scale and matching scale. In particular, we present a comparative study of matching scale uncertainties in the cases of PB-TMD and collinear parton showers.
© The Author(s) 2022
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