Extraction and validation of a new set of CMS pythia8 tunes from underlying-event measurements
File(s)ExtractionAndValidationOfANewSet.pdf (4.89 MB)
Published version
Author(s)
Type
Journal Article
Abstract
New sets of CMS underlying-event parameters (“tunes”) are presented for the pythia8 event generator. These tunes use the NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and the strong coupling evolution at LO or NLO. Measurements of charged-particle multiplicity and transverse momentum densities at various hadron collision energies are fit simultaneously to determine the parameters of the tunes. Comparisons of the predictions of the new tunes are provided for observables sensitive to the event shapes at LEP, global underlying event, soft multiparton interactions, and double-parton scattering contributions. In addition, comparisons are made for observables measured in various specific processes, such as multijet, Drell–Yan, and top quark-antiquark pair production including jet substructure observables. The simulation of the underlying event provided by the new tunes is interfaced to a higher-order matrix-element calculation. For the first time, predictions from pythia8 obtained with tunes based on NLO or NNLO PDFs are shown to reliably describe minimum-bias and underlying-event data with a similar level of agreement to predictions from tunes using LO PDF sets.
Date Issued
2020-01-01
Date Acceptance
2019-11-20
Citation
The European Physical Journal C - Particles and Fields, 2020, 80 (1)
ISSN
1124-1861
Publisher
Springer Verlag (Germany)
Journal / Book Title
The European Physical Journal C - Particles and Fields
Volume
80
Issue
1
Copyright Statement
© CERN for the benefit of the CMS collaboration 2019. Funded by SCOAP3. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Subjects
hep-ex
hep-ex
0206 Quantum Physics
0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
Nuclear & Particles Physics
Publication Status
Published
Article Number
ARTN 4
Date Publish Online
2020-01-03