English

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

High Energy Physics - Experiment 2023-07-13 v3 High Energy Physics - Phenomenology

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\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 (ttˉ\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 ttˉ\mathrm{t\bar{t}} events in the semileptonic channel at 13 TeV.

Keywords

Cite

@article{arxiv.2205.02905,
  title  = {CMS PYTHIA 8 colour reconnection tunes based on underlying-event data},
  author = {CMS Collaboration},
  journal= {arXiv preprint arXiv:2205.02905},
  year   = {2023}
}

Comments

Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/GEN-17-002 (CMS Public Pages)

R2 v1 2026-06-24T11:08:44.297Z