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arXiv · 2205.02905

CMS PYTHIA 8 colour reconnection tunes based on underlying-event data

CMS Collaboration
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Abstract

New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the PYTHIA 8 event generator, are obtained based on the default CMS PYTHIA 8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies $\sqrt{s}$ = 7 and 13 TeV, and by the CDF experiment at 1.96 TeV are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously. The new colour reconnection tunes are compared with various measurements at 1.96, 7, 8, and 13 TeV including measurements of the underlying-event, strange-particle multiplicities, jet substructure observables, jet shapes, and colour flow in top quark pair ($\mathrm{t\bar{t}}$) events. The new tunes are also used to estimate the uncertainty related to colour reconnection modelling in the top quark mass measurement using the decay products of $\mathrm{t\bar{t}}$ events in the semileptonic channel at 13 TeV.

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CMS Collaboration. 2022-05-05. CMS PYTHIA 8 colour reconnection tunes based on underlying-event data. https://doi.org/10.1140/epjc%2Fs10052-023-11630-8

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