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

Authors

A. Tumasyan, CMS Collaboration

Date of this Version

5-16-2023

Citation

Eur. Phys. J. C (2023) 83:587. https://doi.org/10.1140/epjc/s10052-023-11630-8

Comments

Used by permission.

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 √ 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 (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 t[] events in the semileptonic channel at 13 TeV.