Publication Date:
2021-04-01
Description:
This paper presents new sets of parameters (“tunes”) for the underlying-event model of the $${extsc {herwig}} ,7$$ H E R W I G 7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in $${extsc {herwig}} ,7$$ H E R W I G 7 , and are obtained from a fit to minimum-bias data collected by the CMS experiment at $$sqrt{s}=0.9$$ s = 0.9 , 7, and $$13 ,ext {Te}ext {V} $$ 13 Te . The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the data.
Print ISSN:
1434-6044
Electronic ISSN:
1434-6052
Topics:
Physics
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